dissenting.
This ease presents a factual setting that takes place hundreds, if not thousands, of times each day across the country: A Greyhound bus pulled'into the terminal for a brief layover; the .passengers left the bus for a short rest stop and left their carry-on luggage on the bus. What happened after the passengers left the bus has not been as usual: Law enforcement officers boarded the bus and manipulated the luggage in the overhead rack to determine if it contained contraband. After'today, this latter practice may become a frequently observed — and experienced — feature of travel on public transit. Because I believe that the Fourth Amendment protects people in the United States from such an intrusion into their private belongings, I respectfully dissent.
1.
At the outset, it is important to note what this case does not involve. The police did not have probable cause to believe that a controlled substance was on the bus. Indeed, they did not have reasonable suspicion to believe that such was the.ease.1 It is also clear that the officers did not have the permission of the passengers to examine the *1330contents of their on-board luggage. The police officers obtained permission from the bus driver to board the bus and to inspect it without a search warrant. However, there is no indication in the record, nor do my colleagues suggest, that the bus driver validly consented to a police search of the possessions of passengers traveling on his bus.2 There is no evidence that the passengers authorized him to make that decision or that the bus driver had common authority over the property.3 Nor does the record reveal that any signs advised Ms. McDonald that her hand luggage was subject to inspection or search by law enforcement authorities.4
The. officers in this case were not investigating a specific crime or pursuing a particular suspect. Rather, they were conducting a police sweep of the bus on which Ms. McDonald was traveling. This type of general sweep through the bus for narcotics is strictly controlled under the precedent of the Supreme Court.5 Officers may board a bus to question passengers without their activity constituting a seizure as long as the encounter is consensual in nature. Florida v. Bostick, 501 U.S. 429, 434, 111 S.Ct. 2382, 2386, 115 L.Ed.2d 389 (1991). The officers may ask to examine a passenger’s identification and even his luggage as long as they do not require compliance, implicitly or explicitly, with their request. Id. at 437, 111 S.Ct. at 2387 (“We have consistently held that a refusal to cooperate, without more, does not furnish the minimal level of objective justification needed for a detention or seizure.”). In Bostick, “the crucial test is whether, taking into account all of the circumstances surrounding the encounter, the police conduct would ‘have communicated to a reasonable person that he was not at liberty to ignore the police presence and go about his business.’ ” Id. (citations omitted). In this case, no questions were' asked of the passengers *1331before the officers searched the luggage on the bus by feeling and sniffing the bags. Ms. McDonald did not have the opportunity to decline an officer’s request for a search of her bags.
2.
Under these circumstances, the key issue is whether the actions of the officers invaded a legitimate expectation of privacy of Ms. Me Donald. “A ‘search’ occurs when an expectation of privacy that society is prepared to consider reasonable is infringed.” United States v. Jacobsen, 466 U.S. 109, 113, 104 S.Ct. 1652, 1656, 80 L.Ed.2d 85 (1984) (confirming that the public has a legitimate expectation of privacy in letters and packages in transit through the mail or by private carrier). Officers who seek to search private property must respect the “legitimate expectation of privacy” in that property. United States v. Rush, 890 F.2d 45, 48 (7th Cir.1989).
It is well established that a traveler has a legitimate expectation of privacy in his luggage, which is “intended as a repository of personal effects.” United States v. Chadwick, 438 U.S. 1, 13, 97 S.Ct. 2476, 2484, 53 L.Ed.2d 538 (1977), overruled in part, California v. Acevedo, 500 U.S. 565, 111 S.Ct. 1982, 114 L.Ed.2d 619 (1991).6 The Court reiterated this principle in United States v. Place, 462 U.S. 696, 707, 103 S.Ct. 2637, 2644, 77 L.Ed.2d 110 (1983): “We have affirmed that a person possesses a privacy interest in the contents of personal luggage that is protected by the Fourth Amendment.” Our circuit has followed Place in recognizing this privacy interest.7 “For just as the most frail cottage in the kingdom is absolutely entitled to the same guarantees of privacy as the most majestic mansion, so may a traveler who carries a toothbrush and a few articles of clothing in a paper bag or knotted scarf claim an equal right to conceal his possessions from official inspection as the sophisticated executive with the locked attache case.” United States v. Ross, 456 U.S. 798, 822, 102 S.Ct. 2157, 2171, 72 L.Ed.2d 572 (1982).
We therefore must determine the nature and extent of Ms. McDonald’s legitimate expectation of privacy in her luggage when she left it in the rack above her seat during the bus stop in Indianapolis.8 By placing her luggage in a public conveyance, Ms. McDonald certainly had an expectation of privacy less than in her home.9 However, the degree of privacy that she sacrificed depends on the particular circumstances. Here, she did not submit the bags to a search as a condition of her carriage on the bus.10 Nor did she check the luggage or otherwise place it in a situation in which she would lose control over it throughout the journey. While temporarily leaving the bus at an intermediate stop, she left the bags on the bus in the care of the driver of the vehicle.
Placing the luggage in the overhead rack certainly exposed it to certain intrusions. Exposure of the luggage in a public place gives the owner no legitimate expectation of privacy against the “sui generis” intrusion of a sniff by a trained canine. Place, 462 U.S. at 696, 103 S.Ct. at 2639. Ms. McDonald also assumes the risk that the bag might be subjected to the minimal sort of moving that *1332occurs when other passengers seek to place other articles on the same rack. On this basis, our colleagues in other circuits have held that pressing lightly on a bag to facilitate a canine sniff of the air surrounding the bag does not constitute a search of the bag.11 Similarly, the removal of the bag from the overhead rack to a level more commodious for a sniffing canine has been held not to interfere with the legitimate privacy expectations of the owner.12 Therefore, the mere touch of a bag in an overhead rack by an officer has been held not to constitute a search.13
In each of the foregoing situations, the officer’s contact with the bag might be described as the sort of unobtrusive touching that a person expects his property to endure if it is placed on the overhead rack of a bus. We must remember, however, that intrusions into the privacy of another are a matter of degree. Justice White emphasized the need for courts to be sensitive to this question of degree when he wrote for the Court in Minnesota v. Dickerson, 508 U.S. 366, 113 S.Ct. 2130, 124 L.Ed.2d 334 (1993). In that case, police officers, acting with reasonable suspicion, subjected an individual to a pat-down search for weapons. The search revealed no weapons, but the officer felt a lump in the man’s jacket pocket and proceeded to examine it with his fingers. The officer then placed his hand in the man’s jacket and removed the article, which turned out to be contraband. The Supreme Court held that the search had exceeded the scope of the legitimate patdown search for weapons and therefore constituted an impermissible intrusion. Drawing an analogy to the “plain view” doctrine,14 the Court held that, if an officer is engaged in a lawful procedure of touching a suspect for a lawful reason (e.g., the discovery of a weapon), he may seize an illegal substance if the nature of that substance is immediately apparent. Because the officer never believed the object to be a weapon and could not ascertain the nature of the object by limiting himself to the lawful patdown, the remainder of his intrusion into the clothing was constitutionally invalid. Id. at 379, 113 S.Ct. at 2139.
In the case before us, as in Dickerson, it is the degree of intrusion that makes the difference — a constitutional difference — in the lawfulness of the officers’ conduct.15 In Dickerson, the intrusion was lawful as long as it was calculated to discover the weapon that the officer had the right to detect and secure. When the officer penetrated further and conducted an exploratory examination of small items in the defendant’s pockets, his search became unreasonable and the Fourth Amendment was violated. Here, the case law holds that an officer does not intrude on a legitimate expectation of privacy when he examines the air space surrounding a piece of luggage in the overhead compartment of a bus or when he subjects the luggage to the degree of movement that one would expect to encounter in the normal course of travel. If the degree of penetration is greater than what might be normally encountered, the officers’ actions are unreasonable and run afoul of the Amendment’s protection.
As my colleagues note, on factual issues, we owe great deference to the determination of the trial judge. Here, the trial judge described the officer’s actions as “manipulating the sides of the bag with her fingers,” United States v. McDonald, 855 F.Supp. 267, 268 (S.D.Ind.1994), and as “rubbing, squeezing, manipulating,” id. at 269, the bag. This *1333sort of examination of the bag is hardly the sort of occasional touching that a person expects hand luggage to endure in an overhead rack. As the trial court recognized, it was a tactile inspection by an expert examiner aimed at discovering the nature of the contents of the bag, and it involved probing sufficiently intrusive to permit the identification of the internal contents of the bag. Indeed, the intrusion penetrated sufficiently to allow the officer to approximate the number of items in the bag. The owner of the bag, however, has a legitimate expectation of privacy with respect to the contents of the bag. That expectation was violated by the officer’s inspection of the bag in a manner clearly calculated by the degree of its intrusiveness to reveal the contents.
3.
Nor can this illegal search be justified on the rationale that Ms. McDonald abandoned the bag when she failed to identify it at the request of the officer.
A warrantless search of property that has been abandoned is not unreasonable under the Fourth Amendment. Abel v. United States, 362 U.S. 217, 241, 80 S.Ct. 683, 698, 4 L.Ed.2d 668 (1960). In this case the majority wisely does not posit that Ms. McDonald abandoned the luggage when she exited the bus temporarily,' leaving it unattended in a public place. Instead, it treats the suitcases as abandoned because she declined to claim them when the police officer who had conducted the search analyzed above inquired as to the ownership of the bag. An abandonment must be voluntary; if it results from a Fourth Amendment violation, it is not deemed voluntary. United States v. Austin, 66 F.3d 1115, 1118 (10th Cir.1995), cert. denied, — U.S. -, 116 S.Ct. 799, 133 L.Ed.2d 747 (1996). The majority also appropriately concedes that an abandonment can be rendered involuntary by a preceding illegal procedure. However, because the majority is of the view that the officer did not violate Ms. McDonald’s expectation of privacy in her bag, it does not consider this factor in determining whether the bag was abandoned.
When Ms. McDonald returned to the bus, she was confronted by three police officers who, having singled out her bag during her absence by a means then unknown to her, inquired of her, and indeed of all on the bus, as to the ownership of the bag. Although she did not know what had been done to her bag, it was clear that something, yet undisclosed, had occurred in her absence. Ms. McDonald acted well within her rights in refusing to admit ownership of a bag that obviously had been the object of a great deal of police attention during her absence from the bus. The staged ritual of inquiring as to ownership was simply the next step in the illegal police inquiry that began when the bag was rubbed, squeezed and manipulated to ascertain the precise nature of its contents.
4.
Today’s decision is a milestone in the unfolding of the Fourth Amendment jurisprudence of this circuit. In methodology, it is a departure from the decision of the Supreme Court in Dickerson, and from the substantive Fourth Amendment principles of Bostick and Place. The comparative restraint shown by the other circuits in restricting non-consensual examination of luggage to that sort of contact that might reasonably be expected in the normal course of travel is jettisoned.
The practical consequences of this decision are no less substantial than the doctrinal ones. From now on, law enforcement officials in the Seventh Circuit, without probable cause or even reasonable suspicion, may walk throughout public buses and trains and randomly manipulate closed luggage to determine its contents.16 The effectiveness of this *1334investigative methodology certainly can be questioned. Any experienced drug courier now will quickly invest in a hard-shell bag. It is the rest of the traveling public who will bear the onus of today’s holding. No federal judge traveling by bus or rail would expect, or permit, a fellow passenger to rub, squeeze or manipulate his or her hand baggage in a concerted attempt to determine the contents. We should protect for others the privacy that we would demand for ourselves.
. See United States v. Place, 462 U.S. 696, 700-06, 103 S.Ct. 2637, 2641-44, 77 L.Ed.2d 110 (1983) (holding that officers may stop a person in a public place when they have reasonable belief that the person is carrying contraband and may make reasonable inquiry into the circumstances that aroused the suspicion).
. See Illinois v. Rodriguez, 497 U.S. 177, 182-89, 110 S.Ct. 2793, 2798-2802, 111 L.Ed.2d 148 (1990) (consent from individual with apparent authority to consent to search is an exception to a warrantless search).
. See United States v. Matlock, 415 U.S. 164, 171, 94 S.Ct. 988, 993, 39 L.Ed.2d 242 (1974) (noting that consent to search from third party who possessed common authority over property to be inspected may - justify a warrantless search); United States v. Most, 876 F.2d 191, 199-200 (D.C.Cir.1989) (discussing Matlock and consent to search by third parties).
. See McGann v. Northeast III. Regional Commuter R.R. Corp., 8 F.3d 1174, 1182-83 (7th Cir.1993).
. The government quite properly does not attempt to justify the bus sweep operation by analogy to the warrantless search of luggage before boarding an aircraft or under the border search requirement. Those two exceptions have been defined precisely by the case law. In the case of airport searches, the passenger is given warning that the decision to utilize air transport implies a consent to search. See McGann, 8 F.3d at 1179 (noting that courts generally find "that persons presenting themselves at security checkpoints in order to board an airplane ..., knowing by way of a sign or other notice that doing so would subject the persons to search, have impliedly consented to the search performed"). Such a search must, of course, bé narrowly tailored to the purpose for which it was legitimately undertaken. See United States v. Doe, 61 F.3d 107, 109-10 (1st Cir.1995) (positing that "[rjoutine security searches at airport checkpoints pass constitutional muster because the compelling public interest in curbing air piracy generally outweighs their limited intrusiveness”); United States v. De Los Santos Ferrer, 999 F.2d 7, 9 (1st Cir.) (describing airport searches as administrative searches conducted for a "limited — and exigent — purpose”), cert. denied, 510 U.S. 997, 114 S.Ct. 562, 126 L.Ed.2d 462 (1993); United States v. $124,570 U.S. Currency, 873 F.2d 1240, 1243-47 (9th Cir.1989) (describing airport security searches as narrowly limited to their compelling administrative objective of searching for weapons and explosives); cf. United States v. Soyland, 3 F.3d 1312, 1316 (9th Cir.1993) (Kozinski, J., dissenting in part) (discussing administrative searches as "an oddity of Fourth Amendment jurisprudence” that demand proof of a compelling need for the intrusion and strict limitation of that intrusion to the fulfillment of that need), cert. dismissed, Whitalcer v. United States, - U.S. -, 115 S.Ct. 32, 129 L.Ed.2d 928 (1,994).
In the case of border searches, the Supreme Court has been similarly precise in the search of the inquiry. See United States v. Martinez-Fuerte, 428 U.S. 543, 96 S.Ct. 3074, 49 L.Ed.2d 1116 (1976) (approving border checkpoint stops for the purpose of limiting the flow of illegal aliens into the United States); United States v. Johnson, 991 F.2d 1287, 1293 (7th Cir.1993) (noting that, in a routine international border search, a person "could not have reasonably expected that her suitcase would pass through customs without being subjected to an X-ray examination”). The majority's equating of the situation at issue with the x-raying of luggage at an airport or upon *1331entry to public buildings therefore finds no support in established law.
. The Supreme Court abrogated Chadwick's formulation of the automobile exception to the Fourth Amendment in California v. Acevedo, 500 U.S. 565, 573-79, 111 S.Ct. 1982, 1987-91, 114 L.Ed.2d 619 (1991). However, Chadwick is still authority for its articulation of one's expectation of privacy.
. See United States v. Rem, 984 F.2d 806, 809 (7th Cir.), cert. denied, 510 U.S. 913, 114 S.Ct. 300, 126 L.Ed.2d 248 (1993); United States v. Vasquez, 909 F.2d 235, 238 (7th Cir.1990), cert. denied, 501 U.S. 1217, 111 S.Ct. 2826, 115 L.Ed.2d 996 (1991); cf. Bond v. United States, 77 F.3d 1009, 1013 (7th Cir.) (citing Rem for that proposition), cert. denied, - U.S. -, 117 S.Ct. 270, 136 L.Ed.2d 194 (1996).
.See Katz v. United States, 389 U.S. 347, 361, 88 S.Ct. 507, 516-17, 19 L.Ed.2d 576 (1967) (Harlan, J., concurring); see also United States v. Ruth, 65 F.3d 599, 604 (7th Cir.1995), cert. denied, — U.S. -, 116 S.Ct. 1548, 134 L.Ed.2d 651 (1996); United States v. Myers, 46 F.3d 668, 669 (7th Cir.), cert. denied, - U.S. -, 116 S.Ct. 213, 133 L.Ed.2d 144 (1995).
. See Rem, 984 F.2d at 812.
. See Chadwick, 433 U.S. at 13, 97 S.Ct. at 2484.
. See United States v. Lovell, 849 F.2d 910, 915 (5th Cir.1988); United States v. Viera, 644 F.2d 509, 510-11 (5th Cir.), cert. denied, 454 U.S. 867, 102 S.Ct. 332, 70 L.Ed.2d 169 (1981).
. United States v. Harvey, 961 F.2d 1361 (8th Cir.), cert. denied, 506 U.S. 883, 113 S.Ct. 238, 121 L.Ed.2d 173 (1992).
. See United States v. Guzman, 75 F.3d 1090, 1093-95 (6th Cir.), cert. denied, — U.S. -, 117 S.Ct. 266, 136 L.Ed.2d 190 (1996); cf. United States v. Gault, 92 F.3d 990, 992 (10th Cir.), cert. denied, - U.S. -, 117 S.Ct. 321, 136 L.Ed.2d 236 (1996).
. See Michigan v. Long, 463 U.S. 1032, 1050, 103 S.Ct. 3469, 3481, 77 L.Ed.2d 1201 (1983).
. See also Arizona v. Hicks, 480 U.S. 321, 107 S.Ct. 1149, 94 L.Ed.2d 347 (1987) (holding that police, lawfully present to search, because of exigent circumstances, for the perpetrator of a crime, his victims, and weapons, could not seize property not in plain view that they only suspected had been stolen).
. In the strongest possible terms, the majority suggests that the exigencies of modem law enforcement require that the Fourth Amendment, as we and our forebearers have known it, should be sacrificed. Until today no American cotut has tolerated the intrusion permitted here. No American court has allowed the police, acting without any suspicion, any permission, or any exigent circumstances, to intrude deliberately into the privacy of the interior of a person's luggage. It is not one of the "unfortunate realities of today's world” that Fourth Amendment rights have been suspended or abolished because of the exigency of the moment. Judges do not *1334have the authority to work such a radical transformation in basic American liberties simply because they believe that the balance struck by the Framers was inappropriate. Indeed, the judicial task, grounded in our constitutional independence, is to check such attempts, despite their superficial attractiveness to resolve the problems of the moment. What Justice Jackson had to say about the government’s invocation of the War Power ought to be remembered when today we deal with cases involving the war on drugs. See Woods v. CÍoyd W. Miller Co., 333 U.S. 138, 146, 68 S.Ct. 421, 425, 92 L.Ed. 596 (1948) (Jackson, J., concurring) (noting the danger of invoking the War Powers "in haste and excitement when calm legislative consideration of constitutional limitation is difficult”, ... "executed in a time of patriotic fervor that makes moderation unpopular,” and "interpreted by the Judges under the influence of the same passions and pressures”).