United States v. Aaron Graham

ON REHEARING EN BANC

PUBLISHED

UNITED STATES COURT OF APPEALS
FOR THE FOURTH CIRCUIT

No. 12-4659

UNITED STATES OF AMERICA,

Plaintiff - Appellee,

v.

AARON GRAHAM,

Defendant - Appellant.

------------------------------------

ELECTRONIC FRONTIER FOUNDATION; NATIONAL ASSOCIATION OF
CRIMINAL DEFENSE LAWYERS; AMERICAN CIVIL LIBERTIES UNION
FOUNDATION OF MARYLAND; CENTER FOR DEMOCRACY & TECHNOLOGY;
AMERICAN CIVIL LIBERTIES UNION FOUNDATION; DOWNSIZEDC.ORG;
DOWNSIZE DC FOUNDATION; GUN OWNERS FOUNDATION; GUN OWNERS OF
AMERICA, INC.; INSTITUTE ON THE CONSTITUTION; REPORTERS
COMMITTEE FOR FREEDOM OF THE PRESS; UNITED STATES JUSTICE
FOUNDATION; CONSERVATIVE LEGAL DEFENSE AND EDUCATION FUND,

Amici Supporting Appellant.

No. 12-4825

UNITED STATES OF AMERICA,

Plaintiff - Appellee,

v.
ERIC JORDAN,

Defendant - Appellant.

------------------------------------

ELECTRONIC FRONTIER FOUNDATION; NATIONAL ASSOCIATION OF
CRIMINAL DEFENSE LAWYERS; AMERICAN CIVIL LIBERTIES UNION
FOUNDATION OF MARYLAND; CENTER FOR DEMOCRACY & TECHNOLOGY;
AMERICAN CIVIL LIBERTIES UNION FOUNDATION; CONSERVATIVE
LEGAL DEFENSE AND EDUCATION FUND; DOWNSIZEDC.ORG; DOWNSIZE
DC FOUNDATION; GUN OWNERS OF AMERICA, INC.; GUN OWNERS
FOUNDATION; INSTITUTE ON THE CONSTITUTION; REPORTERS
COMMITTEE FOR FREEDOM OF THE PRESS; UNITED STATES JUSTICE
FOUNDATION,

Amici Supporting Appellant.

Appeals from the United States District Court for the District
of Maryland, at Baltimore. Richard D. Bennett, District Judge.
(1:11-cr-00094-RDB-1; 1:11-cr-00094-RDB-2)

Argued: March 23, 2016 Decided: May 31, 2016

Before TRAXLER, Chief Judge, and WILKINSON, NIEMEYER, MOTZ,
KING, GREGORY, SHEDD, DUNCAN, AGEE, KEENAN, WYNN, DIAZ, FLOYD,
THACKER, and HARRIS, Circuit Judges.

Affirmed by published opinion. Judge Motz wrote the majority
opinion, in which Chief Judge Traxler and Judges Wilkinson,
Niemeyer, King, Gregory, Shedd, Duncan, Agee, Keenan, Diaz and
Harris joined. Judge Wilkinson wrote a separate concurring
opinion. Judge Wynn wrote a dissenting opinion in which Judges
Floyd and Thacker joined.

ARGUED: Meghan Suzanne Skelton, OFFICE OF THE FEDERAL PUBLIC
DEFENDER, Greenbelt, Maryland, for Appellants. Rod J.
Rosenstein, OFFICE OF THE UNITED STATES ATTORNEY, Baltimore,
Maryland, for Appellee. ON BRIEF: James Wyda, Federal Public
Defender, OFFICE OF THE FEDERAL PUBLIC DEFENDER, Baltimore,
Maryland, for Appellant Aaron Graham; Ruth Vernet, RUTH J.

2
VERNET, ESQ., LLC, Rockville, Maryland, for Appellant Eric
Jordan. Nathan Judish, Computer Crime & Intellectual Property
Section, UNITED STATES DEPARTMENT OF JUSTICE, Washington, D.C.;
Sujit Raman, Chief of Appeals, Greenbelt, Maryland, Benjamin M.
Block, Assistant United States Attorney, OFFICE OF THE UNITED
STATES ATTORNEY, Baltimore, Maryland, for Appellee. Nathan
Freed Wessler, Catherine Crump, Ben Wizner, AMERICAN CIVIL
LIBERTIES UNION FOUNDATION, New York, New York; David R. Rocah,
AMERICAN CIVIL LIBERTIES UNION FOUNDATION OF MARYLAND,
Baltimore, Maryland; Kevin S. Bankston, Gregory T. Nojeim,
CENTER FOR DEMOCRACY & TECHNOLOGY, Washington, D.C.; Thomas K.
Maher, Vice-Chair, 4th Circuit Amicus Committee, NATIONAL
ASSOCIATION OF CRIMINAL DEFENSE LAWYERS, Durham, North Carolina;
Hanni Fakhoury, ELECTRONIC FRONTIER FOUNDATION, San Francisco,
California, for Amici American Civil Liberties Union Foundation,
American Civil Liberties Union Foundation of Maryland, Center
for Democracy & Technology, Electronic Frontier Foundation, and
National Association of Criminal Defense Lawyers. Michael
Connelly, Ramona, California, for Amicus United States Justice
Foundation; Robert J. Olson, Herbert W. Titus, William J. Olson,
Jeremiah L. Morgan, WILLIAM J. OLSON, P.C., Vienna, Virginia,
for Amici DownsizeDC.org, Downsize DC Foundation, United States
Justice Foundation, Gun Owners of America, Inc., Gun Owners
Foundation, Conservative Legal Defense and Education Fund, and
Institute on the Constitution. Bruce D. Brown, Gregg Leslie,
Hannah Bloch-Wehba, REPORTERS COMMITTEE FOR FREEDOM OF THE
PRESS, Washington, D.C., for Amicus Reporters Committee for
Freedom of the Press.

3
DIANA GRIBBON MOTZ, Circuit Judge:

In United States v. Graham, 796 F.3d 332 (4th Cir. 2015), a

panel of this court affirmed the convictions of Defendants Aaron

Graham and Eric Jordan arising from their participation in a

series of armed robberies. The panel opinion sets out the facts

of this case in great detail. Id. at 339-43. The only facts

now relevant concern the portion of the Government’s

investigation during which it obtained historical cell-site

location information (CSLI) from Defendants’ cell phone

provider. This historical CSLI indicated which cell tower --

usually the one closest to the cell phone -- transmitted a

signal when the Defendants used their cell phones to make and

receive calls and texts. The Government used the historical

CSLI at Defendants’ trial to place them in the vicinity of the

armed robberies when the robberies had occurred.

A majority of the panel held that, although the Government

acted in good faith in doing so, it had violated Defendants’

Fourth Amendment rights when it obtained the CSLI without a

warrant. The majority directed that henceforth the Government

must secure a warrant supported by probable cause before

obtaining these records from cell phone providers. The

Government moved for rehearing en banc, which we granted,

vacating the panel opinion. See United States v. Graham, 624 F.

App’x 75 (4th Cir. 2015); 4th Cir. R. 35(c). We now hold that

4
the Government’s acquisition of historical CSLI from Defendants’

cell phone provider did not violate the Fourth Amendment. 1

Supreme Court precedent mandates this conclusion. For the

Court has long held that an individual enjoys no Fourth

Amendment protection “in information he voluntarily turns over

to [a] third part[y].” Smith v. Maryland, 442 U.S. 735, 743-44

(1979). This rule -- the third-party doctrine -- applies even

when “the information is revealed” to a third party, as it

assertedly was here, “on the assumption that it will be used

only for a limited purpose and the confidence placed in the

third party will not be betrayed.” United States v. Miller, 425

U.S. 435, 443 (1976). All of our sister circuits to have

1
We reinstate the affirmance of Defendants’ convictions and
sentences and adopt the panel opinion with respect to all issues
not addressed in this opinion. We note that, after en banc oral
argument, Defendants moved to file supplemental briefing on a
new claim, based on Johnson v. United States, 135 S. Ct. 2551,
2554 (2015). Defendants argued, for the first time, that
Johnson’s holding rendering 18 U.S.C. § 924(e) void for
vagueness also renders void different language in § 924(c). We
denied the motion as untimely. Even if we were to consider
Defendants’ late claim, however, it would not survive plain
error review. United States v. Carthorne, 726 F.3d 503, 516
(4th Cir. 2013) (“An error is plain ‘if the settled law of the
Supreme Court or this circuit establishes that an error has
occurred.’”). This court has not yet addressed this claim, and
our sister circuits have divided on the issue. Compare United
States v. Vivas–Ceja, 808 F.3d 719, 723 (7th Cir. 2015)
(applying Johnson to find language identical to § 924(c) void
for vagueness), and Dimaya v. Lynch, 803 F.3d 1110, 1120 (9th
Cir. 2015) (same), with United States v. Taylor, 814 F.3d 340,
375-79 (6th Cir. 2016) (declining to find § 924(c) void for
vagueness after Johnson).

5
considered the question have held, as we do today, that the

government does not violate the Fourth Amendment when it obtains

historical CSLI from a service provider without a warrant. In

addition to disregarding precedent, Defendants’ contrary

arguments misunderstand the nature of CSLI, improperly attempt

to redefine the third-party doctrine, and blur the critical

distinction between content and non-content information.

The Supreme Court may in the future limit, or even

eliminate, the third-party doctrine. Congress may act to

require a warrant for CSLI. But without a change in controlling

law, we cannot conclude that the Government violated the Fourth

Amendment in this case.

I.

The Fourth Amendment ensures that “[t]he right of the

people to be secure in their persons, houses, papers, and

effects, against unreasonable searches and seizures, shall not

be violated.” U.S. Const. amend. IV. Broadly, “a Fourth

Amendment search occurs when the government violates a

subjective expectation of privacy that society recognizes as

reasonable.” Kyllo v. United States, 533 U.S. 27, 33 (2001).

The issue that confronts us here is whether the Government’s

acquisition of the historical CSLI records constituted a Fourth

Amendment search.

6
 In assessing whether such a search has occurred, “it is

important to begin by specifying precisely the nature of the

state activity that is challenged.” Smith, 442 U.S. at 741

(emphasis added). Here, that “activity” is the Government’s

acquisition from a phone company, Sprint/Nextel, of historical

CSLI records -- i.e., the records of the phone company that

identify which cell towers it used to route Defendants’ calls

and messages. The Government did not surreptitiously view,

listen to, record, or in any other way engage in direct

surveillance of Defendants to obtain this information. Rather,

as the Sprint/Nextel custodian of the CSLI records testified at

trial, CSLI is created and maintained in the normal course of

Sprint/Nextel’s business. Defendants themselves acknowledge

that service providers, like Sprint/Nextel, maintain CSLI

records “[b]y technical and practical necessity.” Defendants’

Br. at 13. 2

Moreover, to obtain the CSLI from Sprint/Nextel, the

Government had to apply to a federal court for an order

directing the company to disclose the records. The Stored

2
As the Sixth Circuit explained, “[c]arriers necessarily
track their customers’ phones across different cell-site sectors
to connect and maintain their customers’ calls,” and keep CSLI
records “to find weak spots in their network and to determine
whether roaming charges apply, among other purposes.” United
States v. Carpenter, Nos. 14-1572/1805, 2016 WL 1445183, at *4.
(6th Cir. Apr. 13, 2016).

7
Communications Act (SCA or the Act) provides that, to gain

access to even these non-content records, the Government must

demonstrate either probable cause for a warrant or “specific and

articulable facts showing that there are reasonable grounds to

believe that . . . the records . . . are relevant and material

to an ongoing criminal investigation” for a court order. 18

U.S.C. § 2703(c), (d) (2012). The Government followed the

second route and Defendants do not contend that in doing so it

failed to meet the requirements of the Act. What Defendants do

contend is that in permitting the Government to obtain the

Sprint/Nextel records in this way, the Act violates the Fourth

Amendment. According to Defendants, the statute permits the

Government to unconstitutionally collect their private

information.

This argument ignores the nature of the governmental

activity here, which critically distinguishes this case from

those in which the government did unconstitutionally collect

private information. In United States v. Karo, 468 U.S. 705,

714-15 (1984), for instance, the Drug Enforcement Agency placed

a beeper within a can of ether and received tracking information

from the beeper while the can was inside a private residence.

Similarly, in Kyllo, 533 U.S. at 34-35, the Department of the

Interior used a thermal imager to gather “information regarding

the interior of the home.” And in United States v. Jones, 132

8
S. Ct. 945, 948-49, 954 (2012), the FBI and local law

enforcement secretly installed a GPS tracking device on a

suspect’s vehicle and monitored the vehicle’s movements for four

weeks. 3

On the basis of these cases, Defendants contend that the

government always invades an individual’s reasonable expectation

of privacy when it employs technological devices to track an

individual’s moves. Perhaps so. But that question is not

before us. No government tracking is at issue here. Rather,

the question before us is whether the government invades an

individual’s reasonable expectation of privacy when it obtains,

from a third party, the third party’s records, which permit the

government to deduce location information. Karo, Kyllo, and

3 Contrary to Defendants’ suggestion, and unlike the
information in Karo and Jones, the CSLI obtained here does not
enable the government to “place an individual” at home or at
other private locations. The historical CSLI at issue here does
not provide location information anywhere near that specific.
Rather, the record evidence establishes that each of the cell
sites at issue here covers an area with a radius of up to two
miles, and each data point of CSLI corresponds to a roughly 120-
degree sector of a cell site’s coverage area. That means the
CSLI could only determine the four-square-mile area within which
a person used his cell phone. Although we do not think the
applicability of the Fourth Amendment hinges on the precision of
CSLI, it is premature to equate CSLI with the surveillance
information obtained in Karo and Jones.

9
Jones, all of which involve direct government surveillance

activity, tell us nothing about the answer to that question. 4

Instead, the cases that establish the third-party doctrine

provide the answer. Under the third-party doctrine, an

individual can claim “no legitimate expectation of privacy” in

information that he has voluntarily turned over to a third

party. Smith, 442 U.S. at 743-44. The Supreme Court has

reasoned that, by “revealing his affairs to another,” an

individual “takes the risk . . . that the information will be

conveyed by that person to the Government.” Miller, 425 U.S. at

443. The Fourth Amendment does not protect information

voluntarily disclosed to a third party because even a subjective

expectation of privacy in such information is “not one that

society is prepared to recognize as ‘reasonable.’” Smith, 442

U.S. at 743 (internal quotation marks and citation omitted).

The government therefore does not engage in a Fourth Amendment

“search” when it acquires such information from a third party. 5

4
Like these instances of government surveillance, when the
government uses cell-site simulators (often called “stingrays”)
to directly intercept CSLI instead of obtaining CSLI records
from phone companies, the Department of Justice requires a
warrant. See Dep’t of Justice, Department of Justice Policy
Guidance: Use of Cell-Site Simulators 3 (2015), available at
https://www.justice.gov/opa/file/767321/download.
5 Defendants argue that “[t]he government, not the cellular

service providers, surveilled [them].” Defendants’ En Banc Br.
at 7. This is assertedly so because (1) the Communications
Assistance For Law Enforcement Act, 47 U.S.C. § 1002 (2012)
(Continued)
10
 Applying the third-party doctrine to the facts of this

case, we hold that Defendants did not have a reasonable

expectation of privacy in the historical CSLI. The Supreme

Court’s reasoning in Smith controls. There, the defendant

challenged the government’s use of a pen register -- a device

that could record the outgoing phone numbers dialed from his

home telephone. Id. at 737. The Court held that the defendant

could “claim no legitimate expectation of privacy” in the

numbers he had dialed because he had “voluntarily conveyed”

those numbers to the phone company by “‘expos[ing]’ that

information to” the phone company’s “equipment in the ordinary

course of business.” Id. at 744. The defendant thereby

“assumed the risk that the company would reveal to police the

numbers he dialed.” Id.

(CALEA), requires service providers to have the capacity to
allow law enforcement to access CSLI, and (2) service providers
use CSLI in the aggregate, while law enforcement analyzes
individuals’ CSLI to infer their location. Neither argument is
sound. Miller involved a federal statute that similarly
required a service provider (there, a bank) to create and
maintain customer records, and the Supreme Court expressly held
that the statute did not affect the applicability of the third-
party doctrine. See Miller, 425 U.S. at 436, 440-44. Moreover,
the third-party doctrine does not require the government to use
the third party’s records in the same way the third party does.
Third parties maintain records in the ordinary course of their
own business. See Smith, 442 U.S. at 744. That business is
usually not crime-fighting. See, e.g., id. Thus, law
enforcement will almost always use the accessed information for
a different purpose and in a different way than the third party.

11
 Here, as in Smith, Defendants unquestionably “exposed” the

information at issue to the phone company’s “equipment in the

ordinary course of business.” Id. Each time Defendants made or

received a call, or sent or received a text message --

activities well within the “ordinary course” of cell phone

ownership -- Sprint/Nextel generated a record of the cell towers

used. The CSLI that Sprint/Nextel recorded was necessary to

route Defendants’ cell phone calls and texts, just as the dialed

numbers recorded by the pen register in Smith were necessary to

route the defendant’s landline calls. Having “exposed” the CSLI

to Sprint/Nextel, Defendants here, like the defendant in Smith,

“assumed the risk” that the phone company would disclose their

information to the government. Id. at 744. For these reasons,

the Government’s acquisition of that information (historical

CSLI) pursuant to § 2703(d) orders, rather than warrants, did

not violate the Fourth Amendment.

This holding accords with that of every other federal

appellate court that has considered the Fourth Amendment

question before us. Not one has adopted the Defendants’ theory.

Three of our sister courts have expressly held, as we do

today, that individuals do not have a reasonable expectation of

privacy in historical CSLI records that the government obtains

from cell phone service providers through a § 2703(d) order.

See United States v. Carpenter, Nos. 14-1572/1805, 2016 WL

12
1445183, at *4-6 (6th Cir. Apr. 13, 2016) (holding that “for the

same reasons that Smith had no expectation of privacy in the

numerical information at issue [in Smith], the defendants have

no such expectation in the [CSLI] locational information here”);

United States v. Davis, 785 F.3d 498, 511-13 (11th Cir.) (en

banc) (holding that defendant has no “objective[ly] reasonable

expectation of privacy in MetroPCS’s business records showing

the cell tower locations that wirelessly connected his calls”),

cert. denied, 136 S. Ct. 479 (2015); In re Application of U.S.

for Historical Cell Site Data, 724 F.3d 600, 615 (5th Cir. 2013)

(In re Application (Fifth Circuit)) (holding that the government

can use “[s]ection 2703(d) orders to obtain historical cell site

information” without implicating the Fourth Amendment (emphasis

omitted)). And although the fourth of our sister courts opined

that “[a] cell phone customer has not ‘voluntarily’ shared his

location information with a cellular provider in any meaningful

way,” it held that “CSLI from cell phone calls is obtainable

under a § 2703(d) order,” which “does not require the

traditional probable cause determination” necessary for a

warrant. In re Application of U.S. for an Order Directing a

Provider of Elec. Commc’n Serv. to Disclose Records to Gov’t,

620 F.3d 304, 313, 317 (3d Cir. 2010) (In re Application (Third

Circuit)).

13
 Moreover, even in the absence of binding circuit precedent,

the vast majority of federal district court judges have reached

the same conclusion. 6 Defendants are forced to rely on four

inapposite state cases that either interpret broader state

constitutional provisions instead of the Fourth Amendment, or do

6 See, e.g., United States v. Wheeler, No. 15-216, 2016 WL
1048989, at *11-13 (E.D. Wis. Mar. 14, 2016) (Pepper, J.);
United States v. Chavez, No. 3:14-185, 2016 WL 740246, at *2-4
(D. Conn. Feb. 24, 2016) (Meyer, J.); United States v. Epstein,
No. 14-287, 2015 WL 1646838, at *4 (D.N.J. Apr. 14, 2015)
(Wolfson, J.); United States v. Dorsey, No. 14-328, 2015 WL
847395, at *8 (C.D. Cal. Feb. 23, 2015) (Snyder, J.); United
States v. Lang, No. 14-390, 2015 WL 327338, at *3-4 (N.D. Ill.
Jan. 23, 2015) (St. Eve, J.); United States v. Shah, No. 13-328,
2015 WL 72118, at *7-9 (E.D.N.C. Jan. 6, 2015) (Flanagan, J.);
United States v. Martinez, No. 13-3560, 2014 WL 5480686, at *3-5
(S.D. Cal. Oct. 28, 2014) (Hayes, J.); United States v. Rogers,
71 F. Supp. 3d 745, 748-50 (N.D. Ill. 2014)(Kocoras, J.); United
States v. Giddins, 57 F. Supp. 3d 481, 491-94 (D. Md. 2014)
(Quarles, J.); United States v. Banks, 52 F. Supp. 3d 1201,
1204-06 (D. Kan. 2014) (Crabtree, J.); United States v. Serrano,
No. 13-58, 2014 WL 2696569, at *6-7 (S.D.N.Y. June 10, 2014)
(Forrest, J.); United States v. Moreno-Nevarez, No. 13-0841,
2013 WL 5631017, at *1-2 (S.D. Cal. Oct. 2, 2013) (Benitez, J.);
United States v. Rigmaiden, No. 08-814, 2013 WL 1932800, at *14
(D. Ariz. May 8, 2013) (Campbell, J.); United States v. Gordon,
No. 09-153-02, 2012 WL 8499876, at *2 (D.D.C. Feb. 6, 2012)
(Urbina, J.); United States v. Benford, No. 09-86, 2010 WL
1266507, at *2-3 (N.D. Ind. Mar. 26, 2010) (Moody, J.); In re
Applications of U.S. for Orders Pursuant to Title 18, U.S. Code
Section 2703(d), 509 F. Supp. 2d 76, 79-82 (D. Mass. 2007)
(Stearns, J.). But see In re Application for Tel. Info. Needed
for a Criminal Investigation, 119 F. Supp. 3d 1011, 1024 (N.D.
Cal. 2015) (Koh, J.); In re Application of U.S. for an Order
Authorizing Release of Historical Cell-Site Info., 809 F. Supp.
2d 113, 120-27 (E.D.N.Y. 2011) (Garaufis, J.).

14
not consider historical CSLI records, or both. 7 In sum, the

Defendants’ preferred holding lacks support from all relevant

authority and would place us in conflict with the Supreme Court

and every other federal appellate court to consider the

question.

II.

Despite the lack of support for their position, Defendants

insist that the third-party doctrine does not apply here. They

argue that “[a] cell phone user does not even possess the CSLI

to voluntarily convey,” and that even assuming users do convey

such information, “revealing this information is compelled, not

7 Three of the state cases interpret broader state
constitutional protections than the Fourth Amendment. See
Commonwealth v. Augustine, 4 N.E.3d 846, 858 (Mass. 2014)
(finding “no need to wade into the[] Fourth Amendment waters”
when the court could rely on article 14 of the Massachusetts
Declaration of Rights); State v. Earls, 70 A.3d 630, 641-42
(N.J. 2013) (explaining that New Jersey has “departed” from
Smith and Miller and does not recognize the third-party
doctrine); People v. Weaver, 909 N.E.2d 1195, 1201-02 (N.Y.
2009) (“[W]e premise our ruling on our State Constitution
alone.”). In addition to interpreting only the state
constitution, the third case dealt with direct GPS surveillance
by police, not CSLI records procured from a phone company.
Weaver, 909 N.E.2d at 1201-02. And the court in the fourth
state case repeatedly pointed out that it was not considering
“historical cell site location records” -- like those at issue
here -- but “real time cell site location information,” which
had been obtained not through a § 2703(d) order, but under an
order that had authorized only a “pen register” and “trap and
trace device.” Tracey v. State, 152 So.3d 504, 506-08, 515-16,
526 (Fla. 2014).

15
voluntary.” 8 Defendants’ En Banc Br. at 10-11. These arguments

misapprehend the nature of CSLI, improperly attempt to redefine

the third-party doctrine, and rest on a long-rejected factual

argument and the constitutional protection afforded a

communication’s content.

A.

Defendants maintain that cell phone users do not convey

CSLI to phone providers, voluntarily or otherwise. We reject

that contention. With respect to the nature of CSLI, there can

be little question that cell phone users “convey” CSLI to their

service providers. After all, if they do not, then who does?

Perhaps Defendants believe that because a service provider

generates a record of CSLI, the provider just conveys CSLI to

itself. But before the provider can create such a record, it

must receive information indicating that a cell phone user is

relying on a particular cell tower. The provider only receives

that information when a cell phone user’s phone exchanges

signals with the nearest available cell tower. A cell phone

8
Defendants also emphasize the “highly private” nature of
location information. Defendants’ En Banc Br. at 13. But to
the extent they do so to argue that the third-party doctrine
does not apply to CSLI, they are mistaken. The third-party
doctrine clearly covers information that is also considered
“highly private,” like financial records, Miller, 425 U.S. at
441-43, phone records, Smith, 442 U.S. at 743-745, and secrets
shared with confidants, United States v. White, 401 U.S. 745,
749 (1971).

16
user therefore “conveys” the location of the cell towers his

phone connects with to his provider whenever he uses the

provider’s network.

There is similarly little question that cell phone users

convey CSLI to their service providers “voluntarily.” See

Davis, 785 F.3d at 512 n.12 (“Cell phone users voluntarily

convey cell tower location information to telephone companies in

the course of making and receiving calls on their cell

phones.”). This is so, as the Fifth Circuit explained, even

though a cell phone user “does not directly inform his service

provider of the location of the nearest cell phone tower.” In

re Application (Fifth Circuit), 724 F.3d at 614; see also

Carpenter, 2016 WL 1445183, at *5.

Logic compels this conclusion. When an individual

purchases a cell phone and chooses a service provider, he

expects the provider will, at a minimum, route outgoing and

incoming calls and text messages. As most cell phone users know

all too well, proximity to a cell tower is necessary to complete

these tasks. Anyone who has stepped outside to “get a signal,”

or has warned a caller of a potential loss of service before

entering an elevator, understands, on some level, that location

matters. See In re Application (Fifth Circuit), 724 F.3d at 613

(“Cell phone users recognize that, if their phone cannot pick up

17
a signal (or ‘has no bars’), they are out of the range of their

service provider’s network of towers.”).

A cell phone user voluntarily enters an arrangement with

his service provider in which he knows that he must maintain

proximity to the provider’s cell towers in order for his phone

to function. See Carpenter, 2016 WL 1445183, at *5 (“[A]ny

cellphone user who has seen her phone’s signal strength

fluctuate must know that, when she places or receives a call,

her phone ‘exposes’ its location to the nearest cell tower and

thus to the company that operates the tower.”). Whenever he

expects his phone to work, he is permitting -- indeed,

requesting -- his service provider to establish a connection

between his phone and a nearby cell tower. A cell phone user

thus voluntarily conveys the information necessary for his

service provider to identify the CSLI for his calls and texts.

And whether the service provider actually “elects to make a

. . . record” of this information “does not . . . make any

constitutional difference.” Smith, 442 U.S. at 745.

To be sure, some cell phone users may not recognize, in the

moment, that they are “conveying” CSLI to their service

provider. See In re Application (Third Circuit), 620 F.3d at

317. But the Supreme Court’s use of the word “voluntarily” in

Smith and Miller does not require contemporaneous recognition of

18
every detail an individual conveys to a third party. 9 Rather,

these cases make clear that the third-party doctrine does not

apply when an individual involuntarily conveys information -- as

when the government conducts surreptitious surveillance or when

a third party steals private information.

Thus, this would be a different case if Sprint/Nextel had

misused its access to Defendants’ phones and secretly recorded,

at the Government’s behest, information unnecessary to the

provision of cell service. Defendants did not assume that risk

9 If it were otherwise, courts would frequently need to
parse business records for indicia of what an individual knew he
conveyed to a third party. For example, when a person hands his
credit card to the cashier at a grocery store, he may not pause
to consider that he is also “conveying” to his credit card
company the date and time of his purchase or the store’s street
address. But he would hardly be able to use that as an excuse
to claim an expectation of privacy if those pieces of
information appear in the credit card company’s resulting
records of the transaction. Cf. United States v. Phibbs, 999
F.2d 1053, 1077-78 (6th Cir. 1993) (Defendant “did not have both
an actual and a justifiable privacy interest in . . . his credit
card statements.”).
Our dissenting colleagues similarly argue that the third-
party doctrine requires specific “knowledge” on the part of the
phone user about what information is being conveyed at the time.
Because phone users usually do not “know[]” their own CSLI, the
dissent argues, they cannot convey it. But the dissent cannot
have it both ways: Accepting its premise as true for purposes
of argument, we fail to see how a phone user could have a
reasonable expectation of privacy in something he does not know.
Indeed, the dissent rightly questions “whether anyone could
credibly assert the infringement of a legitimate expectation of
privacy” in “numbers dialed by someone else.” The same logic
would also apply to CSLI, which is created “by someone else” --
and of which phone users, according to the dissent, are not even
“aware.”

19
when they made calls or sent messages. But like the defendant

in Smith, 442 U.S. at 745, Defendants here did “assume the risk”

that the phone company would make a record of the information

necessary to accomplish the very tasks they paid the phone

company to perform. They cannot now protest that providing this

essential information was involuntary.

B.

In their efforts to avoid the third-party doctrine,

Defendants attempt to redefine it. They maintain that the

third-party doctrine does not apply to historical CSLI because a

cell phone user does not “actively choose[] to share” his

location information. Defendants’ Br. at 30. Such a rule is

nowhere to be found in either Miller or Smith. Moreover, this

purported requirement cannot be squared with the myriad of

federal cases that permit the government to acquire third-party

records, even when individuals do not “actively choose to share”

the information contained in those records.

For example, courts have attached no constitutional

significance to the distinction between records of incoming

versus outgoing phone calls. The technology the police used in

Smith -- a pen register -- recorded only the numbers dialed by a

suspect’s phone. It did not (and could not) record any

information about incoming calls. To capture that information,

police routinely use a “trap and trace” device. If Defendants

20
were correct that the third-party doctrine applies just when an

individual “actively chooses to share” information, then any

effort to acquire records of incoming phone calls would

constitute a search protected by the Fourth Amendment. After

all, the phone customer never “actively chooses to share” with

the phone company the numbers from incoming telephone calls.

Only the user on the other end of the line, who actually dials

the numbers, does so.

But federal courts have not required a warrant supported by

probable cause to obtain such information. Rather, they

routinely permit the government to install “trap and trace”

devices without demonstrating probable cause. See, e.g., United

States v. Reed, 575 F.3d 900, 914-17 (9th Cir. 2009); United

States v. Hallmark, 911 F.2d 399, 402 (10th Cir. 1990). 10 And

recently we held that police “did not violate the Fourth

Amendment” when obtaining a defendant’s “cellular phone

records,” even though the records included “basic information

10 Our dissenting colleagues posit that perhaps records of
incoming calls have just not been challenged in court. They
have been. See, e.g., In re Application of F.B.I., No. BR 14-
01, 2014 WL 5463097, at *4 (Foreign Intel. Surv. Ct. Mar. 20,
2014) (listing courts that “have relied on Smith in concluding
that the Fourth Amendment does not apply to . . . incoming
calls”); Reed, 575 F.3d at 914 (noting that there is “no Fourth
Amendment expectation of privacy” in “call origination” data);
Sun Kin Chan v. State, 78 Md. App. 287, 300-01(Md. App. 1989)
(“There is no constitutional distinction between the questions
of 1) whom you call and 2) who calls you.”).

21
regarding incoming and outgoing calls on that phone line.”

United States v. Clenney, 631 F.3d 658, 666-67 (4th Cir. 2011)

(emphasis added). 11

Moreover, outside the context of phone records, we have

held that third-party information relating to the sending and

routing of electronic communications does not receive Fourth

Amendment protection. United States v. Bynum, 604 F.3d 161, 164

(4th Cir. 2010). In Bynum, we explained that it “would not be

objectively reasonable” for a defendant to expect privacy in his

phone and Internet subscriber records, including “his name,

email address, telephone number, and physical address.” Id.

Although we had no occasion in Bynum to consider whether an

individual has a protected privacy interest in his Internet

Protocol (IP) address, id. at 164 n.2, several of our sister

circuits have concluded that no such interest exists. See

United States v. Suing, 712 F.3d 1209, 1213 (8th Cir. 2013);

United States v. Christie, 624 F.3d 558, 574 (3d Cir. 2010).

11 Nor has this court ever suggested that other information
typically contained in phone records -- the date, time, and
duration of each call, for example -- merits constitutional
protection. Yet a phone customer never “actively chooses to
share” this information either. Rather, this information is
passively generated and recorded by the phone company without
overt intervention that might be detected by the target user.
If individuals “voluntarily convey,” all of this information to
their phone companies, we see no basis for drawing the line at
the CSLI at issue here. We note that this case deals with only
2010- and 2011-era historical CSLI, generated by texts and phone
calls made and received by a cell phone.

22
 Similarly, the Ninth Circuit has held that “e-mail and

Internet users have no expectation of privacy in . . . the IP

addresses of the websites they visit.” United States v.

Forrester, 512 F.3d 500, 510 (9th Cir. 2008). The Forrester

court also held that there is no reasonable expectation of

privacy in either the to/from addresses of a user’s emails or

the “total amount of data transmitted to or from [a user’s]

account.” Id. at 510-11. The court found the government’s

acquisition of this information “constitutionally

indistinguishable from the use of a pen register that the Court

approved in Smith,” in part because “e-mail and Internet users,

like the telephone users in Smith, rely on third-party equipment

in order to engage in communication.” Id. at 510.

Of course, computer users do “actively choose to share”

some of the information discussed in the above cases, like the

“to” address in an email and the subscriber information conveyed

when signing up for Internet service. But users do not

“actively choose to share” other pieces of information, like an

IP address or the amount of data transmitted to their account.

Internet service providers automatically generate that

information. See Christie, 624 F.3d at 563; cf. Forrester, 512

F.3d at 511. Thus, the redefinition of the third-party doctrine

that Defendants advocate not only conflicts with Supreme Court

23
doctrine and all the CSLI cases from our sister circuits, but is

also at odds with other established circuit precedent.

C.

In another attempt to avoid the third-party doctrine,

Defendants rely on a factual argument long rejected by the

Supreme Court and a series of cases involving the content of

communications to support their assertion that historical CSLI

is protected by the Fourth Amendment.

First, Defendants emphasize that cell phone use is so

ubiquitous in our society today that individuals must risk

producing CSLI or “opt out of modern society.” Defendants’ En

Banc Br. at 11. Defendants contend that such widespread use

shields CSLI from the consequences of the third-party doctrine

and renders any conveyance of CSLI “not voluntary,” for

“[l]iving off the grid . . . is not a prerequisite to enjoying

the protection of the Fourth Amendment.” Id.

But the dissenting justices in Miller and Smith

unsuccessfully advanced nearly identical concerns. Dissenting

in Miller, Justice Brennan contended that “the disclosure by

individuals or business firms of their financial affairs to a

bank is not entirely volitional, since it is impossible to

participate in the economic life of contemporary society without

maintaining a bank account.” 425 U.S. at 451 (Brennan, J.,

dissenting) (internal quotation marks and citation omitted).

24
And dissenting in Smith, Justice Marshall warned that “unless a

person is prepared to forgo use of what for many has become a

personal or professional necessity,” i.e., a telephone, “he

cannot help but accept the risk of surveillance.” 442 U.S. at

750 (Marshall, J., dissenting). It was, in Justice Marshall’s

view, “idle to speak of ‘assuming’ risks in contexts where, as a

practical matter, individuals have no realistic alternative.”

Id. The Supreme Court has thus twice rejected Defendants’

theory. Until the Court says otherwise, these holdings bind us.

Second, Defendants rely on cases that afford Fourth

Amendment protection to the content of communications to suggest

that CSLI warrants the same protection. See Ex parte Jackson,

96 U.S. 727, 733 (1877) (content of letters and packages); Katz

v. United States, 389 U.S. 347, 353 (1967) (content of telephone

calls); United States v. Warshak, 631 F.3d 266, 287-88 (6th Cir.

2010) (content of emails). What Defendants fail to recognize is

that for each medium of communication these cases address, there

is also a case expressly withholding Fourth Amendment protection

from non-content information, i.e., information involving

addresses and routing. See Jackson, 96 U.S. at 733 (no warrant

needed to examine the outside of letters and packages); Smith,

442 U.S. at 743-44 (no reasonable expectation of privacy in

phone numbers dialed); Forrester, 512 F.3d at 510 (no reasonable

expectation of privacy in the to/from addresses of emails);

25
accord Jones, 132 S. Ct. at 957 (Sotomayor, J., concurring)

(noting the Fourth Amendment does not currently protect “phone

numbers” disclosed to phone companies and “e-mail addresses”

disclosed to Internet service providers).

The Supreme Court has thus forged a clear distinction

between the contents of communications and the non-content

information that enables communications providers to transmit

the content. 12 CSLI, which identifies the equipment used to

route calls and texts, undeniably belongs in the non-content

category. As the Sixth Circuit recently recognized, CSLI is

non-content information because “cell-site data -- like mailing

addresses, phone numbers, and IP addresses -- are information

that facilitate personal communications, rather than part of the

content of those communications themselves.” Carpenter, 2016 WL

1445183, at *4.

Defendants disagree with this conclusion. They contend

that CSLI should be treated “as content” because it “record[s] a

person’s movements over a prolonged period,” implicating

“serious . . . privacy concerns.” Defendants’ Br. at 33. But

12In addition to being firmly grounded in the case law, the
content/non-content distinction makes good doctrinal sense. The
intended recipient of the content of communication is not the
third party who transmits it, but the person called, written,
emailed, or texted. The routing and addressing information, by
contrast, is intended for the third parties who facilitate such
transmissions.

26
all routing information “records” some form of potentially

sensitive activity when aggregated over time. For example, a

pen register records every call a person makes and allows the

government to know precisely when he is at home and who he is

calling and credit card records track a consumer’s purchases,

including the location of the stores where he made them. Of

course, CSLI is not identical to either of these other forms of

routing information, just as cell phones are not identical to

other modes of communication. It blinks at reality, however, to

hold that CSLI, which contains no content, somehow constitutes a

communication of content for Fourth Amendment purposes.

Defendants’ attempts to blur this clear distinction 13

further illustrate the extent to which their proposed holding

13Related concerns about a general “erosion of privacy”
with respect to cell phones rest on a similar misapprehension of
this distinction. These concerns revolve around protecting the
large quantity of information stored on modern cell phones and
on remote servers like the “cloud.” See, e.g., Davis, 785 F.3d
at 536 (Martin, J., dissenting). If all that information were
indeed at risk of disclosure, we would share this concern. But
documents stored on phones and remote servers are protected, as
“content,” in the same way that the contents of text messages or
documents and effects stored in a rented storage unit or office
are protected. See, e.g., United States v. Johns, 851 F.2d
1131, 1136 (9th Cir. 1988) (finding that a person renting a
storage unit has a reasonable expectation of privacy in its
contents); United States v. Speights, 557 F.2d 362, 363 (3d Cir.
1977) (finding reasonable expectation of privacy in secured
locker at place of employment). These are clear limiting
principles. Our holding today, that the Government may acquire
with a court order, but without a warrant, non-content routing
(Continued)
27
would be a constitutional outlier -- untenable in the abstract

and bizarre in practice. Case in point: Under Defendants’

theory, the Government could legally obtain, without a warrant,

all data in the Sprint/Nextel records admitted into evidence

here, except the CSLI. If that is so, then the line between a

Fourth Amendment “search” and “not a search” would be the

literal line that, moving left to right across the Sprint/Nextel

spreadsheets, separates the seventh column from the eighth. The

records to the left of that line list the source of a call, the

number dialed, the date and time of the call, and the call’s

duration -- all of which the government can acquire without

triggering Fourth Amendment protection. The records to the

right of that line list the cell phone towers used at the start

and end of each call -- information Defendants’ contend is

protected by the Fourth Amendment. Constitutional distinctions

are made of sturdier stuff.

III.

Technology has enabled cell phone companies, like

Sprint/Nextel, to collect a vast amount of information about

their customers. The quantity of data at issue in this case --

information (including historical CSLI), does not disturb those
principles.

28
seven months’ worth of cell phone records, spanning nearly

30,000 calls and texts for each defendant -- unquestionably

implicates weighty privacy interests.

Outrage at the amount of information the Government

obtained, rather than concern for any legal principle, seems to

be at the heart of Defendants’ arguments. Thus they repeatedly

emphasize the amount of CSLI obtained here and rely on authority

suggesting that the government can obtain a limited amount of

CSLI without a warrant. In response, the panel majority

expressly held that the government can acquire some amount of

CSLI “before its inspection rises to the level of a Fourth

Amendment search.” Graham, 796 F.3d at 350 n.8. But, if as

Defendants maintain, every bit of CSLI has the potential to

“show when a particular individual is home,” and no CSLI is

voluntarily conveyed, Defendants’ Br. at 19-20, then why would

only large quantities of CSLI be protected by the Fourth

Amendment? 14

Defendants’ answer appears to rest on a misunderstanding of

the analysis embraced in the two concurring opinions in Jones.

There, the concurring justices recognized a line between “short-

14The lack of a bright line between permissible and
impermissible amounts of CSLI also stands at odds with the
Supreme Court’s “general preference to provide clear guidance to
law enforcement through categorical rules.” Riley v.
California, 134 S. Ct. 2473, 2491 (2014).

29
term monitoring of a person’s movements on public streets,”

which would not infringe a reasonable expectation of privacy,

and “longer term GPS monitoring,” which would. Jones, 132 S.

Ct. at 964 (Alito, J., concurring in the judgment); see also id.

at 955 (Sotomayor, J., concurring). But Jones involved

government surveillance of an individual, not an individual’s

voluntary disclosure of information to a third party. And

determining when government surveillance infringes on an

individual’s reasonable expectation of privacy requires a very

different analysis.

In considering the legality of the government surveillance

at issue in Jones, Justice Alito looked to what a hypothetical

law enforcement officer, engaged in visual surveillance, could

reasonably have learned about the defendant. He concluded that

four weeks of GPS monitoring by the government constituted a

Fourth Amendment “search” because “society’s expectation” had

always been “that law enforcement agents and others would not --

and indeed, in the main, simply could not -- secretly monitor

and catalogue” an individual’s movements in public for very

long. Id. at 964 (Alito, J., concurring in the judgment)

(emphasis added). In other words, direct surveillance by the

government using technological means may, at some point, be

30
limited by the government’s capacity to accomplish such

surveillance by physical means. 15

However, society has no analogous expectations about the

capacity of third parties to maintain business records. Indeed,

we expect that our banks, doctors, credit card companies, and

countless other third parties will record and keep information

about our relationships with them, and will do so for the

entirety of those relationships -- be it several weeks or many

years. Third parties can even retain their records about us

after our relationships with them end; it is their prerogative,

and many business-related reasons exist for doing so. This is

true even when, in the aggregate, these records reveal sensitive

information similar to what could be revealed by direct

surveillance. For this reason, Justice Alito’s concern in Jones

is simply inapposite to the third-party doctrine and to the

instant case.

Here, Defendants voluntarily disclosed all the CSLI at

issue to Sprint/Nextel. And the very act of disclosure negated

15
We note, though, that such a rule would be unprecedented
in rendering unconstitutional -- because of some later action --
conduct that was undoubtedly constitutional at the time it was
undertaken. See United States v. Sparks, 750 F. Supp. 2d 384,
392 (D. Mass. 2010), aff’d, 711 F.3d 58 (1st Cir. 2013)
(recognizing the aggregation theory as “unworkable” because
“conduct that is initially constitutionally sound could later be
deemed impermissible if it becomes part of the aggregate”).

31
any reasonable expectation of privacy, regardless of how

frequently that disclosure occurred or how long the third party

maintained records of the disclosures. Defendants ignore these

critical facts, attempting to apply the same constitutional

requirements for location information acquired directly through

GPS tracking by the government to historical CSLI disclosed to

and maintained by a third party.

We recognize the appeal -- if we were writing on a clean

slate -- in holding that individuals always have a reasonable

expectation of privacy in large quantities of location

information, even if they have shared that information with a

phone company. But the third-party doctrine does not afford us

that option. Intrinsic to the doctrine is an assumption that

the quantity of information an individual shares with a third

party does not affect whether that individual has a reasonable

expectation of privacy.

Although third parties have access to much more information

now than they did when the Supreme Court decided Smith, the

Court was certainly then aware of the privacy implications of

the third-party doctrine. Justice Stewart warned the Smith

majority that “broadcast[ing] to the world a list of the local

or long distance numbers” a person has called could “reveal the

most intimate details of [that] person’s life.” Smith, 442 U.S.

at 748 (Stewart, J., dissenting). That is, in essence, the very

32
concern that Defendants raise. But the Supreme Court was

unmoved by the argument then, and it is not our place to credit

it now. If individuals lack any legitimate expectation of

privacy in information they share with a third party, then

sharing more non-private information with that third party

cannot change the calculus.

Of course, in the face of rapidly advancing technology,

courts must “assure[] preservation of that degree of privacy

against government that existed when the Fourth Amendment was

adopted.” Kyllo, 533 U.S. at 34. The Supreme Court has long

concluded that the third-party doctrine does this. Thus the

Court has never held that routing information, like CSLI, shared

with third parties to allow them to deliver a message or provide

a service is protected under the Fourth Amendment. Perhaps this

is implicit acknowledgment that the privacy-erosion argument has

a flip-side: technological advances also do not give individuals

a Fourth Amendment right to conceal information that otherwise

would not have been private. 16

16For example, the Smith Court noted that, because a phone
user who “had placed his calls through an operator . . . could
claim no legitimate expectation of privacy” in routing
information exposed to that operator, “a different
constitutional result” did not follow simply “because the
telephone company has decided to automate.” Smith, 442 U.S. at
744-45. Similarly here, “a different constitutional result”
does not follow because the telephone company has decided to
make its phones mobile. Cf. United States v. Skinner, 690 F.3d
(Continued)
33
 Moreover, application of the third-party doctrine does not

render privacy an unavoidable casualty of technological progress

-- Congress remains free to require greater privacy protection

if it believes that desirable. The legislative branch is far

better positioned to respond to changes in technology than are

the courts. See Jones, 132 S. Ct. at 964 (Alito, J., concurring

in the judgment) (“A legislative body is well situated to gauge

changing public attitudes, to draw detailed lines, and to

balance privacy and public safety in a comprehensive way.”); see

also In re Application (Fifth Circuit), 724 F.3d at 615

(explaining that that the proper “recourse” for those seeking

increased privacy is often “in the market or the political

process”).

The very statute at issue here, the Stored Communications

Act (SCA), demonstrates that Congress can -- and does -- make

these judgments. The SCA requires the government to meet a

higher burden when acquiring “the contents of a wire or

electronic communication” from “a provider of electronic

communication service” than when obtaining “a record . . .

pertaining to a subscriber . . . or customer” from the provider.

18 U.S.C. § 2703(a), (c) (emphasis added). It requires the

772, 778 (6th Cir. 2012) (“Law enforcement tactics must be
allowed to advance with technological changes, in order to
prevent criminals from circumventing the justice system.”).

34
executive to obtain judicial approval, as the Government did

here, before acquiring even non-content information. Id.

§ 2703(c), (d). And the SCA is part of a broader statute, the

Electronic Communications Privacy Act of 1986 (ECPA), which

Congress enacted in the wake of Smith. See Pub. L. No. 99-508,

100 Stat. 1848. In the ECPA, Congress responded directly to the

holding in Smith by requiring the government to obtain a court

order (albeit not one supported by probable cause) before

installing a pen register or “trap and trace” device. See 18

U.S.C. § 3121(a) (2012). Although Congress could undoubtedly do

more, it has not been asleep at the switch. 17

Ultimately, of course, the Supreme Court may decide to

revisit the third-party doctrine. Justice Sotomayor has

suggested that the doctrine is “ill suited to the digital age,

in which people reveal a great deal of information about

17Indeed, Congress has been actively considering changes to
the ECPA in recent years based on advances in technology. See
Jared P. Cole & Richard M. Thompson II, Congressional Research
Service, Stored Communications Act: Reform of the Electronic
Communications Privacy Act (ECPA), 8-10 (2015) (describing
various proposed congressional amendments to the ECPA); Scott A.
Fraser, Making Sense of New Technologies and Old Law: A New
Proposal for Historical Cell-Site Location Jurisprudence, 52
Santa Clara L. Rev. 572, 576 (2012) (describing congressional
fact-finding hearings on possible changes to the SCA). And some
state legislatures have recently enacted warrant requirements
for state agencies acquiring historical CSLI. See, e.g., Utah
Code Ann. § 77-23c-102 (West 2015), amended by 2016 Utah Laws
H.B. 369; N.H. Rev. Stat. Ann. § 644-A:2-A:3 (West 2015).
Legislatures manifestly can and are responding to changes in the
intersection of privacy and technology.

35
themselves to third parties in the course of carrying out

mundane tasks.” Jones, 132 S. Ct. at 957 (Sotomayor, J.,

concurring). Indeed, although the Court formulated the third-

party doctrine as an articulation of the reasonable-expectation-

of-privacy inquiry, it increasingly feels like an exception. A

per se rule that it is unreasonable to expect privacy in

information voluntarily disclosed to third parties seems

unmoored from current understandings of privacy. But Justice

Sotomayor also made clear that tailoring the Fourth Amendment to

“the digital age” would require the Supreme Court itself to

“reconsider” the third-party doctrine. Id.

The landscape would be different “if our Fourth Amendment

jurisprudence cease[d] to treat secrecy as a prerequisite for

privacy.” Id. But unless and until the Supreme Court so holds,

we are bound by the contours of the third-party doctrine as

articulated by the Court. See, e.g., Agostini v. Felton, 521

U.S. 203, 237 (1997) (reversing the Second Circuit but noting

that it had correctly applied then-governing law, explaining

that “if a precedent of this Court has direct application in a

case, yet appears to rest on reasons rejected in some other line

of decisions, the Court of Appeals should follow the case which

directly controls” (internal quotation marks, alteration, and

citation omitted)). Applying the third-party doctrine,

consistent with controlling precedent, we can only conclude that

36
the Fourth Amendment did not protect Sprint/Nextel’s records of

Defendants’ CSLI. Accordingly, we hold that the Government

legally acquired those records through § 2703(d) orders.

IV.

For the reasons set forth above, we affirm in all respects

the judgment of the district court.

AFFIRMED

37
WILKINSON, Circuit Judge, concurring:

I am pleased to concur in Judge Motz’s fine opinion. The

court rightly holds that obtaining historical cell site location

information (CSLI) from a third party cell phone provider is not

a search under the Fourth Amendment. Any result to the contrary

would be at odds with the Supreme Court and decisions from our

sister circuits. I write separately to emphasize my concern that

requiring probable cause and a warrant in circumstances such as

these needlessly supplants the considered efforts of Congress

with an ill-considered standard of our own.

Appellants appear to think that the Framers drafted the

Constitution with the judiciary alone in mind. I do not deny

that the judiciary has an important, indeed critical, role to

play in interpreting the Fourth Amendment. But I fear that by

effectively rewriting portions of a federal statute under the

guise of reasonableness review courts run the risk of boxing the

democratic branches out of the constitutional dialogue. For good

reason, developing constitutional meaning has always been a

collaborative enterprise among the three departments of

government. The present case offers a perfect example of why

that is so.

I.

In enacting Title II of the Electronic Communications

Privacy Act of 1986, popularly known as the Stored

38
Communications Act (SCA), 18 U.S.C. § 2701 et seq., Congress did

not behave in a flippant or haphazard fashion. Instead, it

crafted a thorough statutory framework limiting the government’s

ability to gather wire and electronic communication data from

communications service providers (here, Sprint/Nextel). The

SCA’s “comprehensive remedial scheme,” Kelley v. Fed. Bureau of

Investigation, 67 F. Supp. 3d 240, 271 (D.D.C. 2014), “creates a

set of Fourth Amendment-like privacy protections by statute,

regulating the relationship between government investigators and

service providers in possession of users’ private information.”

Sams v. Yahoo! Inc., 713 F.3d 1175, 1179 (9th Cir. 2013)

(quoting Orin S. Kerr, A User’s Guide to the Stored

Communications Act, and a Legislator’s Guide to Amending It, 72

Geo. Wash. L. Rev. 1208, 1212 (2004)).

At the heart of the SCA lies § 2703. That provision

establishes a calibrated set of procedural safeguards based on

the type and amount of information sought and the length of time

the records are stored. For instance, “only pursuant to a

warrant,” 18 U.S.C. § 2703(a), can the government obtain the

contents of a communication that is in electronic storage with a

service provider for 180 days or less. Alternatively, the

government has a number of options for compelling the disclosure

of non-content customer records, or the contents of

communications in electronic storage for more than 180 days:

39
“obtain[] a warrant,” id. §§ 2703(b)(1)(A), (c)(1)(A), “use[] an

administrative subpoena . . . or trial subpoena,” id.

§ 2703(b)(1)(B)(i), or “obtain[] a court order.”

Id. §§ 2703(b)(1)(B)(ii), (c)(1)(B).

Here, the government secured a court order for the

disclosure of non-content communication records (specifically,

CSLI) pursuant to § 2703(c)(1)(B). Congress set forth the

requirements for a valid court order in § 2703(d), which

mandates that the government supply “specific and articulable

facts showing that there are reasonable grounds to believe that

the contents of a wire or electronic communication, or the

records or other information sought, are relevant and material

to an ongoing criminal investigation.” Id. § 2703(d). In other

words, § 2703(d) “is essentially a reasonable suspicion

standard.” In re U.S. for an Order Pursuant to 18 U.S.C. Section

2703(d), 707 F.3d 283, 287 (4th Cir. 2013).

I see no reason to depart from Congress’s carefully

tailored scheme. As the majority points out, the SCA in fact

exceeds the constitutional floor established by the Supreme

Court, whose decisions hold that the Fourth Amendment does not

apply to information voluntarily conveyed to third parties. Ante

at 9-10; see, e.g., Smith v. Maryland, 442 U.S. 735, 743-44

(1979); United States v. Miller, 425 U.S. 435, 443 (1976).

Although appellants would insert their own impressions of the

40
Fourth Amendment into § 2703(d) by way of a warrant and probable

cause requirement, that approach not only aspires to overturn

Supreme Court rulings but to scuttle the laborious efforts of

the Congress to balance privacy and law enforcement interests in

a responsible way.

II.

It has long been the case that developing constitutional

meaning is not a responsibility that rests solely on the

shoulders of the judiciary. It has instead been “a power and

duty shared by all three branches, and its shared nature

suggests that it ought not be fulfilled by each branch acting

independently within its sphere of authority.” Dawn E. Johnsen,

Functional Departmentalism and Nonjudicial Interpretation: Who

Determines Constitutional Meaning?, 67 Law & Contemp. Probs.

105, 121 (2004). Formulation of constitutional guidance, in

other words, is a collaborative enterprise, “with each branch

encouraged to recognize its own institutional limitations and to

respect the superior competencies of the others.” Id. at 120. *

*My dissenting friend rightly lauds the function of
judicial review, see Marbury v. Madison, 5 U.S. 137, 178 (1803),
but effectively dismisses respect for Congress’s efforts as one
component of that review. See post at 65-66 n. 14. This, of
course, envisions a process where the judiciary speaks only to
itself, a curiously monologic exercise at odds with the
constitutional structure of American government.
Not to worry, says the dissent. All it is doing is
“eliminating a single line of statutory text, specifically 18
(Continued)
41
 This principle applies with special force where Congress

has weighed in on the Fourth Amendment’s requirement of

“reasonableness.” That term, of course, “is not capable of

precise definition or mechanical application.” Bell v. Wolfish,

441 U.S. 520, 559 (1979). Faced with a term literally crying out

for balance between the competing interests of individual

privacy and societal security, it is appropriate to accord some

degree of deference to legislation weighing the utility of a

particular investigative method against the degree of intrusion

on individuals’ privacy interests. See United States v. Jones,

132 S. Ct. 945, 963-64 (2012) (Alito, J., concurring).

In this setting, Congress brings several cards to the

table. First, it enjoys a relatively greater degree of access

than courts to expert opinion generally and to the expertise of

the executive branch in particular. Trial courts, of course,

hear expert testimony all the time, but they are to a

considerable extent at the mercy of the parties whose witnesses

may be called to serve a narrow set of interests rather than the

interests of the public at large. Appellate amicus briefs and

U.S.C. § 2703(c)(1)(B).” Id. But “eliminating” a critical option
Congress has provided in favor of the dissent’s idea of what is
best for us is the kind of constitutional club that ends the
conversation and severely limits opportunities for legislative
reforms and responses in what is a rapidly evolving field.

42
arguments are helpful to be sure, but not enough, I think, to

close the expertise gap or compensate for the large differences

in size between congressional and judicial staffs. The more

technical the issue (as the one before us surely is), the more

salient the expertise differential may prove to be. It is not

surprising, then, that “[t]hroughout our history . . . it has

been Congress that has taken the lead in . . . balanc[ing] the

need for a new investigatory technique against the undesirable

consequences of any intrusion on constitutionally protected

interests in privacy.” Dalia v. United States, 441 U.S. 238, 264

(1979) (Stevens, J., dissenting). That tradition is a sound one,

for it not only reflects an understanding of our own

institutional limitations, but the value of having democratic

backing behind Fourth Amendment balancing.

Second, Congress is often better positioned to achieve

legal consistency. Abandoning Congress’s comprehensive effort

for particularized and improvised judicial standards invites

confusion into what has been a relatively stable area of the

law. See ante at 10-13. The SCA -- which remains “the primary

vehicle by which to address violations of privacy interests in

the communication field,” Adams v. City of Battle Creek, 250

F.3d 980, 986 (6th Cir. 2001) -- promotes uniformity by focusing

the courts’ inquiry on a prescribed set of conditions that must

be satisfied before disclosure will be compelled. See, e.g., 18

43
U.S.C. § 2703(d). Detailed statutory standards have at least as

fair a chance of achieving clear guidance and consistency as

court developed rules. Congress’s aim of consistency would be

imperiled, however, if courts become willing to strike this or

that portion of the statute to accommodate what may be their

unique privacy policy views. In my judgment, uniform national

standards rather than regional variations among the courts has

merit where Congress has comprehensively legislated in a

particular field.

Finally, Congress imparts the considerable power of

democratic legitimacy to a high stakes and highly controversial

area. The emergence of advanced communication technologies has

set off a race between criminal enterprises on the one hand and

law enforcement efforts on the other. Modern communication

devices -- even as they abet the government’s indigenous

tendencies to intrude upon our privacy -- also assist criminal

syndicates and terrorist cells in inflicting large-scale damage

upon civilian populations. Appellants’ strict standard of

probable cause and a warrant even for non-content information

held by third parties thus risks an imbalance of the most

dangerous sort, for it allows criminals to utilize the latest in

technological development to commit crime and hamstrings the

ability of law enforcement to capitalize upon those same

developments to prevent crime. The fact that the appellants in

44
this case were convicted of Hobbs Act violations and brandishing

offenses cannot obscure the implications of their proposed

standards for much more serious threats down the road.

In my view, striking a balance in an area rife with the

potential for mass casualty cannot leave democracy out in the

cold. Courts must continue to play a vital role in Fourth

Amendment interpretation, but in large matters of life and death

the people’s representatives must also play their part. See,

e.g., Donovan v. Dewey, 452 U.S. 594, 603 (1981) (Congress’s

authorization of warrantless inspections of surface and

underground mines deemed constitutional under the Fourth

Amendment in light of the “notorious history of serious

accidents” causing large loss of life in the mining industry).

It is naive, I think, for the judicial branch to assume

insensitivity to privacy concerns on the part of our elected

brethren. Just last year, for example, a bipartisan Congress

terminated the National Security Agency’s collection of bulk

phone records. Uniting and Strengthening America by Fulfilling

Rights and Ensuring Effective Discipline Over Monitoring Act of

2015 (USA Freedom Act), Pub. L. No. 114-23, 129 Stat. 268. Other

statutes make Congress’s privacy concerns abundantly clear. See,

e.g., Privacy Act of 1974, Pub. L. No. 93-579, 88 Stat. 1896

(codified at 5 U.S.C. § 552a (2012)); Omnibus Crime Control and

45
Safe Streets Act of 1968, Pub. L. No. 90-351, 82 Stat. 197

(codified as amended at 18 U.S.C. § 2510 et seq. (2012)).

It is human nature, I recognize, to want it all. But a

world of total privacy and perfect security no longer exists, if

indeed it ever did. We face a future of hard tradeoffs and

compromises, as life and privacy come simultaneously under

siege. How sad, near the very inception of this journey, for

appellants to adopt the most stringent of Fourth Amendment

standards, to discard the great values of democratic compromise,

and to displace altogether the legislative role.

46
WYNN, Circuit Judge, with whom FLOYD and THACKER, Circuit
Judges, join, dissenting in part and concurring in the judgment: 1

A customer buys a cell phone. She turns it on and puts it

in her pocket. With those acts, says the majority, she has

“voluntarily conveyed” an unbounded set of personal location

data to her service provider, all of which is unprotected by the

Fourth Amendment. Here, that included 221 days’ worth of

information, amounting to roughly 29,000 location-identifying

data points for each Defendant.

The majority further claims that “Supreme Court precedent

mandates this conclusion,” that “[l]ogic compels” it. Ante, at

5, 17. But those contentions are difficult to square with the

array of concurring and dissenting opinions that have already

been issued by federal appellate judges on this subject. 2 With

1 In accordance with the practice of my colleague, see
United States v. Graham, 796 F.3d 332, 378 n.1 (4th Cir. 2015)
(Motz, J., dissenting in part and concurring in the judgment), I
have styled this opinion as a partial dissent. Even though I
would affirm the Defendants’ convictions under the exclusionary
rule’s good-faith exception, I take issue with the majority’s
determination that there was no Fourth Amendment violation, a
conclusion which “will have profound consequences in future
cases in the Fourth Circuit.” Id.
2 Four other federal appellate courts have issued five
decisions considering as a matter of first impression the
applicability of the Fourth Amendment to CSLI, and those
decisions generated seven concurring or dissenting opinions.
See United States v. Carpenter, Nos. 14-1572, 14-1805, 2016 WL
1445183, at *1 (6th Cir. Apr. 13, 2016) (majority opinion); id.
at *11 (Stranch, J., concurring); United States v. Davis, 785
F.3d 498, 500 (11th Cir. 2015) (en banc) (majority opinion); id.
at 519 (W. Pryor, J., concurring); id. at 521 (Jordan, J.,
(Continued)
47
respect for the differing view of my colleagues in the majority,

this is not an easy issue. Not only that, but a close reading

of the Supreme Court’s third-party doctrine demonstrates that

cell site location information (CSLI) is not “voluntarily

conveyed” by cell phone users. It is therefore not beyond the

Fourth Amendment’s reach.

I.

A.

The third-party doctrine operates to bar Fourth Amendment

protection only for information that has been “voluntarily

conveyed” by an individual to a third party. The majority does

not dispute this limitation, see ante, at 10–11, 16–18, nor

could it. That phrase, or some slight variation of it, appears

without exception as a necessary analytical component in each of

the Supreme Court’s founding third-party doctrine cases. Smith

concurring); id. at 524 (Rosenbaum, J., concurring); id. at 533
(Martin, J., dissenting); United States v. Davis, 754 F.3d 1205
(11th Cir.) (unanimous), vacated, reh’g en banc granted, 573 F.
App’x 925 (11th Cir. 2014); In re Application of the U.S. for
Historical Cell Site Data, 724 F.3d 600, 602 (5th Cir. 2013) (In
re Application (Fifth Circuit)) (majority opinion); id. at 615
(Dennis, J., dissenting); In re Application of U.S. for an Order
Directing a Provider of Elec. Commc’n Serv. to Disclose Records
to Gov’t, 620 F.3d 304, 305 (3d Cir. 2010) (In re Application
(Third Circuit)) (majority opinion); id. at 319 (Tashima, J.,
concurring). The only unanimous panel held that the
government’s warrantless acquisition of CSLI constituted a
Fourth Amendment violation. Davis, 754 F.3d at 1215. No doubt,
when the votes are tallied, more now support the majority’s
position. But that should not decide this case.

48
v. Maryland, 442 U.S. 735, 744 (1979) (“When he used his phone,

petitioner voluntarily conveyed numerical information to the

telephone company . . . .” (emphasis added)); id. at 745

(“[P]etitioner voluntarily conveyed to [the phone company]

information that it had facilities for recording . . . .”

(emphasis added)); United States v. Miller, 425 U.S. 435, 442

(1976) (“All of the documents obtained, including financial

statements and deposit slips, contain only information

voluntarily conveyed to the banks . . . .” (emphasis added));

Hoffa v. United States, 385 U.S. 293, 302 (1966) (“Neither this

Court nor any member of it has ever expressed the view that the

Fourth Amendment protects a wrongdoer’s misplaced belief that a

person to whom he voluntarily confides his wrongdoing will not

reveal it.” (emphasis added)); Lewis v. United States, 385 U.S.

206, 212 (1966) (“[This case] presents no question of the

invasion of the privacy of a dwelling; the only statements

repeated were those that were willingly made to the agent and

the only things taken were the packets of marihuana voluntarily

transferred to him.” (emphasis added)); see also United States

v. White, 401 U.S. 745, 749 (1971) (no Fourth Amendment

protection where an individual “voluntarily confides his

wrongdoing” to another (quoting Hoffa, 385 U.S. at 302)).

The Supreme Court, then, has intentionally employed the

“voluntary conveyance” concept in every relevant case to limit

49
the reach of an otherwise sweeping per se rule that denies

Fourth Amendment protection. It seems therefore crucial here to

ask: what, precisely, did the Court mean when it chose those

words, in the context of those cases?

Here is what those various defendants actually did to

“voluntarily convey” information. One used his finger to dial,

one by one, the numerical digits of a telephone number. Smith,

442 U.S. at 741 (highlighting that pen registers disclose “only

the telephone numbers that have been dialed” (quoting United

States v. N.Y. Tel. Co., 434 U.S. 159, 167 (1977))). Another

submitted multiple checks and deposit slips—each presumably

bearing a date, a dollar amount, a recipient name, and a

personal signature. Miller, 425 U.S. at 442. The others

actually spoke. White, 401 U.S. at 746–47 (conversations with a

bugged government informant related to narcotics transactions);

Hoffa, 385 U.S. at 296 (statements to an associate “disclosing

endeavors to bribe [jury] members”); Lewis, 385 U.S. at 210

(conversations with an undercover law enforcement agent in the

course of executing a narcotics sale).

In all of these cases—the only cases that can bind us here—

“voluntary conveyance” meant at least two things. First, it

meant that the defendant knew he was communicating particular

information. We can easily assume Miller knew how much money he

was depositing, that Smith knew the numbers he was dialing, and

50
that Hoffa, Lewis, and White knew about the misconduct they

verbally described to another.

Second, “voluntary conveyance” meant that the defendant had

acted in some way to submit the particular information he knew.

Crucially, there was an action—depositing, dialing, speaking—

corresponding to each piece of submitted information. And where

many data pieces were compiled into records—financial records in

Miller, phone records in Smith—there was presumptively a

discrete action behind each piece of data. The Court never

suggested that the simple act of signing up for a bank account,

or a phone line, was enough to willingly turn over thousands of

pages of personal data.

These two components of “voluntary conveyance”—knowledge of

particular information and an action submitting that

information—were thus present in every “Supreme Court precedent”

that can “mandate[] [our] conclusion” here. Ante, at 5. Those

features also characterize the vast majority of cases where the

third-party doctrine has been applied by other federal courts.

When a credit card holder signs a receipt that includes the

address of the vendor, the bill amount, and the time of the

transaction, she both indicates her knowledge of that particular

51
information and acts to submit it. 3 Thus, courts have held that

the third-party doctrine applies to credit card records. E.g.,

United States v. Phibbs, 999 F.2d 1053, 1077-78 (6th Cir. 1993);

see also United States v. Maturo, 982 F.2d 57, 59 (2d Cir. 1992)

(credit card records admitted as evidence); United States v.

Kragness, 830 F.2d 842, 865 (8th Cir. 1987) (same).

When someone types “his name, email address, telephone

number, and physical address” into a form and then submits that

information to a service provider in order to secure internet

access, he not only has knowledge of the typed information but

has affirmatively acted to communicate it. United States v.

Bynum, 604 F.3d 161, 164 (4th Cir. 2010). Thus, courts have

held that the third-party doctrine applies to subscriber

3
The majority argues that reading “voluntary conveyance” to
require user knowledge would require courts “frequently . . . to
parse business records [such as credit card records] for indicia
of what an individual knew he conveyed to a third party.” Ante,
at 19 n.9. That argument is a bogeyman. Courts would not need
to “parse” credit card records to determine whether the
cardholder at a grocery knew he was conveying “the date and time
of his purchase or the store’s street address,” id., any more
than the Supreme Court had to “parse” Miller’s bank records to
determine whether he knew he was conveying the date, amount, or
recipient name that appeared on the checks he himself had
endorsed. That much was obvious from the nature of the record
and the transactions it reflected. Where user knowledge cannot
be easily ascertained in this manner, however, I would not force
an ill-fitting presumption of voluntariness in order to strip
Fourth Amendment protection from a defendant. See Ohio v.
Robinette, 519 U.S. 33, 40 (1996) (“[V]oluntariness is a
question of fact to be determined from all the circumstances.”
(quoting Schneckloth v. Bustamonte, 412 U.S. 218, 248–49
(1973))).

52
information. Id.; see also United States v. Perrine, 518 F.3d

1196, 1204 (10th Cir. 2008) (collecting cases).

When an internet user types a URL—which is uniquely linked

to a single IP address 4—into her web browser and hits the “Enter”

key, she knows the web address and she actively submits it.

Thus, although the law in this area is still unsettled, courts

have generally concluded that the third-party doctrine applies

to the IP addresses of visited websites. See, e.g., United

States v. Forrester, 512 F.3d 500, 510 (9th Cir. 2008) (“Like

telephone numbers . . . e-mail to/from addresses and IP

addresses are not merely passively conveyed through third party

equipment, but rather are voluntarily turned over in order to

direct the third party’s servers.”). 5

4 See United States v. Forrester, 512 F.3d 500, 510 n.5 (9th
Cir. 2008) (“Every computer or server connected to the Internet
has a unique IP address. A website typically has only one IP
address even though it may contain hundreds or thousands of
pages. For example, Google’s IP address is 209.85.129.104 and
the New York Times’ website’s IP address is 199.239.137.200.”).
5 One category of generally admitted third-party information

would not be “voluntarily conveyed” under my reading of that
requirement: phone records of incoming calls. See ante, at 20—
22. Perhaps one reason such information is routinely admitted
is that it is rarely challenged by defendants, since it is
outgoing call information that tends to be incriminating, as was
the case in the sole authority from this circuit cited by the
majority. See United States v. Clenney, 631 F.3d 658, 662 (4th
Cir. 2011) (investigator “confirmed through phone records that
[defendant’s] phone number was the source of outgoing calls”).
Regardless, it is an open question whether anyone could credibly
assert the infringement of a legitimate expectation of privacy
in the numbers dialed by someone else (as one can in her
(Continued)
53
 It follows that knowledge of particular information and a

corresponding act transmitting that information have defined

“voluntary conveyance” in virtually every case espousing or

applying the third-party doctrine, and certainly in every case

that can bind us here. Those features describe traditional bank

records and phone records, hotel bills and airline miles

statements, email addresses and social media profile

information. This is a description—not a redefinition—of the

third-party doctrine. 6

B.

The foregoing discussion makes clear that CSLI is not

“voluntarily conveyed” by a cell phone user, and therefore is

not subject to the third-party doctrine.

movements over time, see infra section II). In other words, my
view of “voluntary conveyance” may not require excluding
warrantlessly procured incoming call information. Even if it
did, that would be a small price to pay for preserving the
substance of a constitutionally mandated limitation on the
third-party doctrine’s scope.
6 Indeed, it is the majority who has “improperly attempt[ed]

to redefine the third-party doctrine.” Ante, at 6; see also
ante, at 16, 20. The majority recasts the Supreme Court’s
“voluntary conveyance” language in a double negative, such that
“the third-party doctrine does not apply when an individual
involuntarily conveys information.” Ante, at 19 (first emphasis
added). The upshot of this approach is that the protections of
the Fourth Amendment are limited to situations where “the
government conducts surreptitious surveillance or when a third
party steals private information.” Id. While the majority
might prefer to preserve Fourth Amendment protection only for
information that is not coercively seized, that is not the
Supreme Court’s standard, and it should not be ours.

54
 First, consider how little a cell phone user likely knows

about his CSLI. Unlike the deposit amounts in Miller and the

phone numbers in Smith, which were at various points made

obvious to the user “in the ordinary course of business,” Smith,

442 U.S. at 744, there is no reason to think that a cell phone

user is aware of his CSLI, or that he is conveying it. He does

not write it down on a piece of paper, like the dollar amount on

a deposit slip, or enter it into a device, as he does a phone

number before placing a call. Nor does CSLI subsequently appear

on a cell phone customer’s statement, as the relevant

information did for the banking customer in Miller and the phone

caller in Smith. See Smith, 442 U.S. at 742 (“All subscribers

realize . . . that the phone company has facilities for making

permanent records of the numbers they dial, [because] they see a

list of their . . . calls on their monthly bills.”).

Consequently, “it is unlikely that cell phone customers are

aware that their cell phone providers collect and store [CSLI].”

In re Application of U.S. for an Order Directing a Provider of

Elec. Commc’n Serv. to Disclose Records to Gov’t, 620 F.3d 304,

317 (3d Cir. 2010) (In re Application (Third Circuit)). And

even if cell phone customers have a vague awareness that their

location affects the number of “bars” on their phone, see ante,

at 18, they surely do not know which cell phone tower their call

will be routed through, a fact even the government concedes.

55
Appellee’s Br. at 53 (“[T]he location of the cell phone tower

handling a customer’s call is generated internally by the phone

company and is not typically known by the customer.”). User

knowledge, the first component of “voluntary conveyance,” is

therefore essentially absent. 7

Second, consider what the cell phone user does—or does not

do—to transmit CSLI. As a general matter, “CSLI is purely a

function and product of cellular telephone technology, created

by the provider’s system network at the time that a cellular

telephone call connects to a cell site.” Commonwealth v.

Augustine, 4 N.E.3d 846, 862 (Mass. 2014). In some instances,

CSLI is produced when a user places an outgoing call, an action

7 The majority “fail[s] to see how a phone user could have a
reasonable expectation of privacy in something he does not
know.” Ante, at 19 n.9. I wonder: does the majority imagine
that Danny Kyllo knew what levels of infrared radiation emanated
from his home and were recorded with precision by the
government’s thermal imaging device? See Kyllo v. United States,
533 U.S. 27, 29–30 (2001). The rule that one must “know” what
one can reasonably expect to keep private is new to me, and I
believe to Fourth Amendment doctrine as well. It is also yet
another aspect of this Court’s present decision with troubling
future implications. I suppose we can also expect no privacy in
data transmitted by networked devices such as the “Fitbit”
bracelet, which “can track the steps you take in a day, calories
burned, and minutes asleep”; the “Scanadu Scout,” which can
“measure your temperature, heart rate, and hemoglobin levels”;
or the “Mimo Baby Monitor ‘onesie’ shirt,” which can “monitor
your baby's sleep habits, temperature, and breathing patterns.”
Scott R. Peppet, Regulating the Internet of Things: First Steps
Toward Managing Discrimination, Privacy, Security, and Consent,
93 Tex. L. Rev. 85, 88 (2014); see also infra note 8. Making
knowledge requisite to privacy is inconsistent not only with
Supreme Court precedent but with our basic societal norms.

56
that arguably corresponds with the generated information (even

if the user remains unaware of that information). However, CSLI

is also generated when a phone simply receives a call, even if

the user does not answer. In these instances, CSLI is

automatically generated by the service provider’s network,

without any user participation at all. See In re Application

(Third Circuit), 620 F.3d at 317–18 (“[W]hen a cell phone user

receives a call, he hasn’t voluntarily exposed anything at

all.”). 8

8 The majority does not take seriously this idea—that
information might be automatically generated without user
involvement. See ante, at 16 (“[T]here can be little question
that cell phone users ‘convey’ CSLI to their service providers.
After all, if they do not, then who does?”); id. (“Perhaps
Defendants believe that . . . the [service] provider just
conveys CSLI to itself.”). But even in the era of Miller and
Smith, human beings were not the only entities capable of
collecting and conveying information. That is also surely the
case now, and will only become increasingly relevant going
forward. See, e.g., Neil M. Richards, The Dangers of
Surveillance, 126 Harv. L. Rev. 1934, 1940 (2013) (“The
incentives for the collection and distribution of private data
are on the rise. The past fifteen years have seen the rise of
an Internet in which personal computers and smartphones have
been the dominant personal technologies. But the next fifteen
will likely herald the ‘Internet of Things,’ in which networked
controls, sensors, and data collectors will be increasingly
built into our appliances, cars, electric power grid, and homes,
enabling new conveniences but subjecting more and more
previously unobservable activity to electronic measurement,
observation, and control.”); Peppet, supra note 7, at 88–89.
Today, the majority saddles us with a rule that does not
distinguish between information an individual himself conveys
and information that computerized devices automatically record,
generate, and transmit. In other words, the majority’s
expansive interpretation of Miller and Smith will, with time,
(Continued)
57
 In sum, because a cell phone customer neither possesses

knowledge of his CSLI nor acts to disclose it, I agree with the

Third Circuit that he “has not ‘voluntarily’ shared his location

information with a cellular provider in any meaningful way.”

Id. at 317; accord Augustine, 4 N.E.3d at 862; Tracey v. State,

152 So. 3d 504, 525 (Fla. 2014). 9

II.

Because CSLI is not voluntarily conveyed to service

providers, the third-party doctrine alone cannot resolve whether

the government here conducted a Fourth Amendment “search.” In

other words, there must be an independent evaluation of whether

“the government violates a subjective expectation of privacy

that society recognizes as reasonable” by acquiring large

gather momentum—with effects increasingly destructive of
privacy.
9 Because CSLI is not voluntarily conveyed by cell phone

users, I find it unnecessary to wade into the murky waters that
separate “content” from “non-content” information. The point of
the “content” designation, as recognized by the Supreme Court,
is that even some information that is voluntarily conveyed to
(or routed through) third parties is nevertheless protected by
the Fourth Amendment. For example, even though one voluntarily
conveys information by speaking into a public telephone
receiver, “the contents of [those] communications” are
protected. Smith, 442 U.S. at 741. The voluntarily conveyed
content contained in a letter, Ex parte Jackson, 96 U.S. 727,
733 (1877), or in the body of an e-mail, United States v.
Warshak, 631 F.3d 266, 288 (6th Cir. 2010), is protected, too.
But where the information in question was never voluntarily
conveyed in the first place, the third-party doctrine should
have no application, even if that information is deemed “non-
content.”

58
amounts of CSLI. Kyllo v. United States, 533 U.S. 27, 33 (2001)

(citing Katz v. United States, 389 U.S. 347, 361 (1967) (Harlan,

J., concurring)). To answer that question, an examination is

warranted of both the quality and quantity of the information

the government here acquired.

The government obtained 221 days of CSLI for each

Defendant. 10 That amounted to 29,659 location data points for

Graham (an average of 134 data location points per day) and

28,410 location data points for Jordan (an average of 129

location points per day). Each piece of data revealed not only

the particular cell tower through which the relevant call was

routed, but also a particular 120-degree sector—or one-third

“slice”—within that cell tower’s range. The record indicates

that the cell sites at issue in this case covered a circular

area with a radius no larger than two miles. But given the

density of cell sites in urban areas like Baltimore, where

Sprint/Nextel operates 79 cell sites within the city limits and

many more in Baltimore County, the relevant cell site area was

likely far more precise for much of the location data obtained.

10 This CSLI acquisition far eclipses any a federal
appellate court has previously approved. Cf. Carpenter, 2016 WL
1445183, at *3 (considering two CSLI acquisitions, for separate
defendants, spanning 88 and 127 days); Davis, 785 F.3d at 515
(CSLI acquisition spanning 67 days); In re Application (Fifth
Circuit), 724 F.3d at 608 n.9 (CSLI acquisition spanning 60
days).

59
The records reveal extensive details about Defendants’ locations

and movements throughout the seven months-long period. For

Graham, over two thousand calls were initiated and terminated in

different cell site sectors, indicating movement during the

call. Some days offer particularly telling data. For example,

during one 38-hour period in October 2010, Graham made and

received 209 calls located in 55 different cell site sectors.

In United States v. Jones, 132 S. Ct. 945 (2012), the

Supreme Court unanimously held that the government’s

installation of a GPS device on a suspect’s vehicle and its use

of that device to track the vehicle’s movements over a 28-day

period violated the Fourth Amendment. See id. at 949, 954; id.

at 964 (Alito, J., concurring in the judgment). A majority of

the Court agreed that “longer term GPS monitoring in

investigations of most offenses impinges on expectations of

privacy.” Id. at 955 (Sotomayor, J., concurring); id. at 964

(Alito, J., concurring in the judgment). 11 That conclusion was

rooted in concerns about the government’s ability to capture

data describing an individual’s movements and aggregate that

11
That is, five Justices agreed that longer-term location
monitoring could violate an individual’s reasonable expectation
of privacy. Although the majority opinion was grounded in a
trespass-based rationale, see id. at 949, it made clear that
“[s]ituations involving merely the transmission of electronic
signals without trespass would remain subject to [reasonable
expectation of privacy] analysis,” id. at 953.

60
data “to ascertain, more or less at will,” private information

about an individual, such as her “political and religious

beliefs, sexual habits, and so on.” Id. at 956 (Sotomayor, J.,

concurring). While the Justices left it an open question how

long location surveillance could occur before triggering Fourth

Amendment protection, Justice Alito clarified that “the line was

surely crossed before the 4–week mark.” Id. at 964.

Here, we confront a locational data set that is on the

whole more invasive than the one considered in Jones.

Admittedly, the CSLI acquired here, which could trace an

individual to a neighborhood even if not to a specific address,

was less precise than the GPS tracking information in Jones.

“But precision is not the only variable with legal

significance.” United States v. Carpenter, Nos. 14-1572, 14-

1805, 2016 WL 1445183, at *12 (6th Cir. Apr. 13, 2016) (Stranch,

J., concurring). Quantity matters, too. And in my view, the

sheer volume of data the government acquired here decides this

case. 12

12
The majority wonders “why . . . only large quantities of
CSLI [would] be protected by the Fourth Amendment.” Ante, at
29. That is a fair question to ask of Defendants, who maintain
that even smaller amounts of CSLI can be used to peer “into the
home.” Appellants’ Br. at 20. In my view, however, the CSLI
utilized here was not precise enough to implicate an
individual’s privacy interest in the home’s interior. See
United States v. Karo, 468 U.S. 705, 714–16 (1984).
Consequently, I consider the main privacy expectation infringed
(Continued)
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 Whereas the Supreme Court deemed the government’s

collection of 28 days of location data unconstitutional, the

data challenged here spans 221 days—nearly eight times the

surveillance period evaluated in Jones. The Eleventh Circuit

concluded that a 67-day set of CSLI could “[w]ithout question

. . . when closely analyzed, reveal certain patterns with regard

to [the defendant’s] physical location in the general vicinity

of his home, work, and indeed the robbery locations.” United

States v. Davis, 785 F.3d 498, 516 (11th Cir. 2015) (en banc).

I have little trouble concluding that the close analysis of a

221-day CSLI set would reveal much more, potentially “enabl[ing]

the Government to ascertain, more or less at will, [an

individual’s] political and religious beliefs, sexual habits,

and so on.” Jones, 132 S. Ct. at 956 (Sotomayor, J.,

concurring).

here to be in Defendants’ movements over an extended period of
time, which necessarily requires examining the quantity of data
obtained. Furthermore, I agree that “[i]ntrinsic to the [third-
party] doctrine is an assumption that the quantity of
information an individual shares . . . does not affect whether
that individual has a reasonable expectation of privacy.” Ante,
at 32. That is, in part, why the majority’s holding is so
troublingly broad. See infra section III. But having
determined that CSLI is not voluntarily conveyed, and thus that
the third-party doctrine does not decide this case, I must
evaluate separately whether a reasonable expectation of privacy
has been infringed. Because the basis for my decision is
extrinsic to the third-party doctrine, it is natural that I
would not be bound by an “intrinsic . . . assumption” of that
doctrine.

62
 By acquiring vast quantities of Defendants’ location

information, spanning months, without Defendants’ consent, the

government infringed their reasonable expectations of privacy

and thereby engaged in a search. Because that search was

warrantless, it violated the Fourth Amendment. 13

III.

Even more disquieting to me than the result the majority

has reached today is the path it has chosen to reach it.

The majority does not decide, for instance, as did the

Third Circuit, that the CSLI employed here was too imprecise or

too discontinuous to infringe Defendants’ privacy. See In re

Application (Third Circuit), 620 F.3d at 312–13. That narrower

holding would have allowed this Court to grapple, in the future,

with the effect of rapidly changing phone technology, like the

increasing “proliferation of smaller and smaller [cell sites]

such as microcells, picocells, and femtocells—which cover a very

specific area, such as one floor of a building, the waiting room

of an office, or a single home,” In re Application for Tel.

Info. Needed for a Criminal Investigation, 119 F. Supp. 3d 1011,

13“[A]s a general matter, warrantless searches ‘are per se
unreasonable under the Fourth Amendment . . . .’” City of
Ontario, Cal. v. Quon, 560 U.S. 746, 760 (2010) (quoting Katz,
389 U.S. at 357). In my view, none of the “few specifically
established and well-delineated exceptions” to that rule apply
here. Id.

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1023 (N.D. Cal. 2015), or the advent of smartphone “pinging,”

whereby location data can be generated almost continuously, see,

e.g., In re Application of U.S. for an Order Authorizing

Disclosure of Location Info. of a Specified Wireless Tel., 849

F. Supp. 2d 526, 534 (D. Md. 2011). Rather, the majority

concedes what follows unavoidably from its holding: “the

applicability of the Fourth Amendment [does not] hinge[] on the

precision of CSLI,” ante, at 9 n.3, or on its quantity, ante, at

32. The Supreme Court has cautioned that “[w]hile the

technology used in the present case [may be] relatively crude,

the rule we adopt must take account of more sophisticated

systems that are already in use or in development.” Kyllo, 533

U.S. at 36. Suppose the same case arises in two years, now

featuring months of GPS-pinpointed location data, down to the

second. Apply the majority’s rule. Same result.

Neither does the majority hold, as the Eleventh Circuit did

in the alternative, that the court order required by 18 U.S.C.

§ 2703(d), though less than a warrant backed by probable cause,

nevertheless satisfied the Fourth Amendment’s reasonableness

“touchstone.” See Davis, 785 F.3d at 516–18; id. at 521–24

(Jordan, J., concurring). That holding would have at least

preserved a modicum of Fourth Amendment protection for the

location data at issue here, requiring an evaluation of the

relevant statutory provision that “assess[es], on the one hand,

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the degree to which [the search] intrudes upon an individual's

privacy and, on the other, the degree to which it is needed for

the promotion of legitimate governmental interests.” Id. at 517

(quoting Wyoming v. Houghton, 526 U.S. 295, 300 (1999)). If

that were the Court’s holding, then the majority’s token

assurances that “Congress . . . has not been asleep at the

switch,” ante, at 35, and my concurring colleague’s laudatory

musings about Congress’s “striking a balance in an area rife

with the potential for mass casualty,” ante, at 45, might do

more than salve our judicial consciences: they would actually be

doctrinally relevant. 14 But as it is, Congress could repeal the

14
My concurring colleague joins the majority based on his
“fear that by effectively rewriting portions of a federal
statute under the guise of reasonableness review courts run the
risk of boxing the democratic branches out of the constitutional
dialogue.” Ante, at 38. If that is truly the grounds for his
concurrence, I hope my friend understands that the majority’s
opinion today will be the last word spoken in that “dialogue.”
It is a conversation ender. Following today’s decision, the
judiciary will have absolutely no role in articulating what
protections the Fourth Amendment requires for private
information that is not either directly gathered by the
government or secretively stolen by third parties. We have thus
avoided “boxing out” the other branches, but only at the cost of
boxing out ourselves. So much for a “collaborative enterprise
among the three departments of government.” Ante, at 38. By
the way, the statutory “rewriting” my colleague fears would
require eliminating a single line of statutory text,
specifically 18 U.S.C. § 2703(c)(1)(B). The efficiency of that
modification is possible because Congress, as my colleague
recognizes, provided in its “carefully tailored scheme,” ante,
at 40, that the government could acquire non-content customer
information by obtaining a warrant. 18 U.S.C. § 2703(c)(1)(A).
One wonders whether Congress itself might have anticipated the
(Continued)
65
SCA and the ECPA tomorrow. Apply the majority’s rule. Same

result.

What this elucidates is the extraordinary breadth of the

majority’s decision today. It is not bounded by the relative

precision of location data, by the frequency with which it is

collected, or by the statutory safeguards Congress has thought

it prudent to enact. The majority’s holding, under the guise of

humble service to Supreme Court precedent, markedly advances the

frontlines of the third-party doctrine. The Fourth Amendment,

necessarily, is in retreat.

IV.

Only time will tell whether our society will prove capable

of preserving age-old privacy protections in this increasingly

networked era. But one thing is sure: this Court’s decision

today will do nothing to advance that effort. I dissent.

potential for a contrary decision today. Finally, although I
appreciate my colleague’s civics lesson on the institutional
competencies of Congress, I would remind him of one of our own:
judicial review. See Marbury v. Madison, 5 U.S. 137, 178
(1803).

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