concurring in part and dissenting in part:
This case raises the question whether a person whom a prosecutor can rightly arrest under a statute becomes wrongly arrested if the prosecutor’s purpose in arresting him had nothing to do with the statute. Put another way, can a prosecutor, empowered by law to arrest an individual for one declared purpose, be immune from suit when he arrests that person with another, secret purpose in mind?
Our natural reaction is, “Of course not!” Such a prosecutor is abusing the vast discretionary powers we have entrusted to him. He is not playing fair; he is playing “Gotcha!”
But under our law, that natural reaction would be wrong. For reasons of public policy, our law provides the prosecutor with official immunity — perhaps not immunity from being fired, impeached, or hounded from public life, but immunity nonetheless — from lawsuits for money damages based on the acts he undertakes on behalf of the public.
The Supreme Court has developed this law by repeatedly instructing us not to inquire into the personal, subjective intentions of a government official when determining whether the official is protected by official immunity. Reading the minds of government officials is notoriously expensive, uncertain, and fraught with error. The very purpose of official immunity is to shield the purses of government officials from the high costs of civil damages lawsuits. If official immunity were to depend upon proof of the officials’ good intentions, the value of that immunity would be lost.
Yet today, the majority permits plaintiff Abdullah al-Kidd to seek redress from the wallet of a federal cabinet-level official for injuries al-Kidd alleges he suffered when he was detained — pursuant to a warrant signed and issued by a neutral federal magistrate judge — as a material witness in the government’s prosecution of an indicted terrorist suspect.
The sole reason the majority provides for stripping former Attorney General John Ashcroft of his official immunity is that, although he and his subordinates had sufficient evidence to arrest al-Kidd as a material witness in the prosecution of a suspected terrorist under the applicable statute, they acted with a forbidden state of mind: they really arrested him not to *982testify against the indicted terror suspect, but to investigate al-Kidd himself.
Because I do not believe this holding comports with the Supreme Court’s instructions regarding official immunity and Fourth Amendment law, I must respectfully dissent.
I also dissent from the majority’s resolution of al-Kidd’s claim that Ashcroft is personally liable for the inclusion of claimed material misrepresentations and omissions in the affidavit supporting the material witness warrant on which al-Kidd was detained. Al-Kidd’s complaint does not state facts sufficient plausibly to show Ashcroft was personally responsible for the claimed falsities. See Ashcroft v. Iqbal, — U.S. -, 129 S.Ct. 1937, 173 L.Ed.2d 868 (2009).
I. Background
After 9/11, in connection with an investigation into terrorist activities in Idaho, federal agents interviewed al-Kidd on several occasions. In February 2003, a grand jury returned an indictment against Sami Omar Al-Hussayen, a suspect in that investigation. During the course of the investigation, FBI agents learned, and later affied, that al-Kidd had received “in excess” of $20,000 from Al-Hussayen, had met with Al-Hussayen’s associates after al-Kidd’s trip to Yemen, and had contacts with the Islamic Assembly of North America (“IANA”) (the suspected Jihadist organization for which Al-Hussayen worked).1 One month later, al-Kidd purchased a plane ticket to Saudi Arabia. Apprehensive, they said, that al-Kidd would abscond to Saudi Arabia with information critical to the prosecution of al Hussayen, never to return, the federal agents sought a warrant for his arrest. The agents appeared before a magistrate, swore they had good cause to believe al-Kidd both had information material to Al-Hussayen’s prosecution and was on the run, and then arrested al-Kidd at Dulles International Airport as he was about to board a plane to Saudi Arabia. The government held alKidd for fourteen days and released him only when al-Kidd surrendered his passport and agreed to certain conditions of release. In the event, al-Kidd was never called to testify at al-Hussayen’s trial.
Al-Kidd filed this action under Bivens v. Six Unknown Named Agents, 403 U.S. 388, 91 S.Ct. 1999, 29 L.Ed.2d 619 (1971), in the United States District Court for the District of Idaho. Al-Kidd named as defendants not only the officers who prepared the material witness warrant, but former Attorney General Ashcroft, FBI Director Robert Mueller, and former Secretary of the Department of Homeland Security Michael Chertoff, as well as the wardens of the prisons in which he was detained. In his complaint, al-Kidd raises three very distinct claims. First, al-Kidd alleges that the conditions under which he was confined were unconstitutionally harsh. Second, al-Kidd alleges his detention on a material witness warrant was illegal because it was based on pure pretext; the government wanted to detain alKidd not to secure his testimony at the Al-Hussayen trial but really to keep al-Kidd himself off the streets and to investigate him. Al-Kidd contends that even if the warrant on which he was detained was *983objectively valid, the preparing officers’ subjective intention to use the warrant to accomplish an illicit goal rendered the officers’ actions unconstitutional. Third, alKidd contends the warrant was not only illegal because it was pretextual, it was also invalid because it was based on an affidavit containing material misrepresentations and omissions: Al-Kidd had no information useful to the investigation, he was not a flight risk, and the government knew it but concealed those facts from the magistrate.
Ashcroft contends each of these claims is barred, either because al-Kidd has not pleaded facts sufficient to establish Ashcroft’s personal involvement; because Ashcroft enjoys absolute or qualified immunity against al-Kidd’s claims; or, because the district court lacked personal jurisdiction over Ashcroft.
The majority concludes that al-Kidd has not adequately pleaded Ashcroft’s personal involvement in the decision to subject him to unconstitutionally harsh conditions of confinement. I agree, and therefore I join in Part B.5 of the majority opinion (“The Conditions of Confinement Claim”).
As to al-Kidd’s second and third claims, however, the majority affirms the district court’s order denying Ashcroft’s motion to dismiss.
I disagree. As to al-Kidd’s claim prosecutors used the material witness statute as a pretext to pursue other, investigatory or crime prevention agendas, the answer is simply that such pretext does not invalidate the arrest warrant; I would hold Ashcroft is shielded by qualified immunity. In light of the considerable authority recognizing that the pretextual use of an objectively justifiable search or seizure does not violate the Fourth Amendment, it follows the federal agents did not violate al-Kidd’s constitutional rights. But if I’m wrong, in any case al-Kidd’s right not to be arrested on an objectively valid, but pretextual arrest warrant was not “clearly established” in March 2003, when al-Kidd was detained, and qualified immunity therefore shields Ashcroft from al-Kidd’s claims. See Saucier v. Katz, 533 U.S. 194, 121 S.Ct. 2151, 150 L.Ed.2d 272 (2001). I therefore dissent from part B.3 of the majority opinion (“The Fourth Amendment Claim”).
As to al-Kidd’s claim that his detention violated the Fourth Amendment and the terms of the material witness statute because the supporting warrant application contained material misrepresentations and omissions, we cannot reach the merits of his claim, for — as with his claim that Ashcroft is liable for the claimed wretched conditions of al-Kidd’s confinement, as to which all of us agree his claim fails — alKidd has failed to allege facts sufficient to establish Ashcroft’s personal liability for such conduct. See Ashcroft v. Iqbal, 556 U.S.-, 129 S.Ct. 1937, 173 L.Ed.2d 868 (2009). Therefore I dissent from part B.4 of the majority opinion.
Lastly, I disagree, in part, with the majority’s treatment of Ashcroft’s claim of absolute immunity. I agree that Ashcroft lacks absolute prosecutorial immunity , for his acts or omissions in supervising the officers who acted as complaining witnesses in support of a material witness warrant application. When officials— whether prosecutors or police officers — act as mere witnesses in support of a warrant application, absolute immunity does not shield their actions. Equally, Ashcroft would lack absolute immunity for his acts or omissions in supervising officers who obtain a material witness warrant to secure the presence of a witness before an investigatory grand jury, rather than a criminal trial. However, I disagree that Ashcroft does not enjoy absolute immunity for his supervision of prosecutors who decide to seek a material witness warrant to *984secure the presence of a witness at a criminal trial, regardless of any claimed improper motive.2
I address each of these issues in turn.
II. Qualified Immunity
I would hold that Ashcroft enjoys qualified immunity from al-Kidd’s claim that the material witness warrant on which he was detained was merely a pretext to accomplish other law enforcement objectives. To be clear, al-Kidd’s pretext claim is not that the material witness warrant on which he was detained was invalid on its face or because it was based on an affidavit containing material misrepresentations or omissions.3 Rather, in his pretext claim, al-Kidd contends that even if the material witness warrant on which he was detained was objectively valid and supported by probable cause, the prosecutor’s subjective intention to use the material witness warrant to accomplish other, law-enforcement objectives renders the government’s conduct unconstitutional. Because al-Kidd had no constitutional right to be free from such conduct — and certainly had no dearly established constitutional right — I dissent from the majority’s conclusion that Ashcroft lacks qualified immunity.
Al-Kidd bases his claims of liberty from arrest on the Fourth Amendment. The Supreme Court has repeatedly stated that under the Fourth Amendment, an officer’s subjective intentions are irrelevant so long as the officer’s conduct is objectively justified. See, e.g., Maryland v. Macon, 472 U.S. 463, 470-71, 105 S.Ct. 2778, 86 L.Ed.2d 370 (1985) (“Whether a Fourth Amendment violation has occurred turns on an objective assessment of the officer’s actions in light of the facts and circumstances confronting him at the time, and not on the officer’s actual state of mind at the time the challenged action was taken.” (internal citations and quotation marks omitted));4 Scott v. United States, 436 U.S. 128, 136-37, 98 S.Ct. 1717, 56 L.Ed.2d 168 (1978) (“Subjective intent alone, the Government contends, does not make otherwise lawful conduct illegal or unconstitutional. We think the Government’s position, which also served as the basis for decision in the Court of Appeals, embodies the proper approach for evaluating compliance with the minimization requirement [relating to wiretaps].”);5 United States v. *985Robinson, 414 U.S. 218, 236, 94 S.Ct. 467, 38 L.Ed.2d 427 (1973) (holding that an officer’s objectively lawful search incident to arrest was lawful though officer lacked the subjective intention — fear that the arrestee was armed — that normally attaches to such searches).
Whren v. United States, 517 U.S. 806, 116 S.Ct. 1769, 135 L.Ed.2d 89 (1996), cited by the majority, is but one example of the general rule that pretextual searches and seizures do not violate the Fourth Amendment. In Whren, the Supreme Court held the stop of a vehicle for a minor traffic violation did not violate the Fourth Amendment even though the officer was using the stop “as pretext[] for pursuing other investigatory agendas.” Id. at 811, 116 S.Ct. 1769. The Court stated:
We [have] flatly dismissed the idea that an ulterior motive might serve to strip the agents of their legal justification.... [S]ubjeetive intent alone ... does not make otherwise lawful conduct illegal or unconstitutional. We described Robinson [414 U.S. at 236, 94 S.Ct. 467] as having established that “the fact that the officer does not have the state of mind which is hypothecated by the reasons which provide the legal justification for the officer’s action does not invalidate the action taken as long as the circumstances, viewed objectively, justify that action.”
Id. at 812-13, 116 S.Ct. 1769 (internal citations omitted). It is really quite simple. If you are engaged in conduct that justifies your detention, you must put up with that detention, even if the officer who detained you did so out of some secret — and constitutionally insufficient — motive.
There is good reason to eschew inquiry into the subjective motivations of individual officers. First, such an approach provides “arbitrarily variable” protection to individual rights. Devenpeck v. Alford, 543 U.S. 146, 154, 125 S.Ct. 588, 160 L.Ed.2d 537 (2004). If the subjective intentions of the arresting officers are the touchstone of constitutional analysis, courts may reach divergent results about searches and seizures that are utterly indistinguishable in the eyes of the person whose rights are at stake. See id. at 154, 125 S.Ct. 588.6 Second, the inquiry into *986subjective intentions is impossibly difficult, expensive, and prone to error. As the Supreme Court explained in Harlow v. Fitzgerald,
[tjhere are special costs to subjective inquiries of this kind.... Judicial inquiry into subjective motivation therefore may entail broad-ranging discovery and the deposing of numerous persons, including an official’s professional colleagues. Inquiries of this kind can be peculiarly disruptive of effective government.
457 U.S. 800, 816-817, 102 S.Ct. 2727, 73 L.Ed.2d 396 (1982) (footnotes and internal quotation marks omitted). Whren, along with Harlow, Robinson, Scott, and Macon, makes clear that al-Kidd’s arrest on an objectively valid warrant supported by probable cause violated none of al-Kidd’s constitutional rights. At a minimum, these cases would have given a reasonable officer good reason to believe that al-Kidd’s arrest was constitutionally permissible.
The majority’s efforts to distinguish Whren are unpersuasive. The majority contends that Whren and like cases are inapplicable whenever the government acts without probable cause to believe that the subject of the arrest is guilty of some criminal wrongdoing. Maj. Op. at 966-67. To reach this result, the majority imports the “programmatic purpose” test ordinarily reserved for administrative or “special needs” search cases. The programmatic purpose test, of course, tests the constitutional validity of warrantless searches and seizures, such as drunk driving roadblocks, by requiring the government to prove its program serves governmental interests other than the routine collection of evidence for criminal prosecution. See, e.g., Ferguson v. City of Charleston, 532 U.S. 67, 78, 121 S.Ct. 1281, 149 L.Ed.2d 205 (2001); City of Indianapolis v. Edmond, 531 U.S. 32, 45, 121 S.Ct. 447, 148 L.Ed.2d 333 (2000). The special needs cases are the sole exception to the general principle that, in testing compliance with the Fourth Amendment, courts are limited to an examination of the objective circumstances which justify the search or seizure, and may not inquire into official purpose. Whren, 517 U.S. at 812, 116 S.Ct. 1769 (“Not only have we never held, outside the context of inventory search or administrative inspection!,] ... that an officer’s motive invalidates objectively justifiable behavior!,] ... we have repeatedly held and asserted the contrary.”). The programmatic purpose test applies here, the majority says, because in Edmonds, the Supreme Court said that Whren did not apply whenever the government conducted a search or seizure without “probable cause,” and because “probable cause” means only probable cause to believe the subject of the arrest committed some wrongdoing. The cases the majority cites offer no support whatsoever for the majority’s approach.
First, the special needs cases have no bearing on the inquiry into al-Kidd’s arrest for the simple reason that al-Kidd was arrested pursuant to a warrant issued by a neutral magistrate. The “programmatic purpose” inquiry is necessary to test the validity of a special needs search precisely because such searches occur without the procedural protections of the warrant requirement and the magisterial supervision it entails. As the Supreme Court explained in New York v. Burger, a statute authorizing a warrantless administrative or special needs search must provide
a constitutionally adequate substitute for a warrant. In other words, the regulatory statute must perform the two basic functions of a warrant: it must advise the owner of the commercial premises *987that the search is being made pursuant to the law and has a properly defined scope, and it must limit the discretion of the inspecting officers.
482 U.S. 691, 710-11, 107 S.Ct. 2636, 96 L.Ed.2d 601 (1987) (emphasis added) (quotations omitted). Material witness warrants, though not based on individualized suspicion of wrongdoing are, of course, warrants: they are based on an individualized determination that the subject of the warrant is in possession of information material in a criminal proceeding and is likely to flee; they are approved by a neutral magistrate; they are subject to continuing oversight; and they issue only upon a showing of probable cause. Bacon v. United States, 449 F.2d 933, 942 (9th Cir.1971); 18 U.S.C. §§ 3144; Fed. R.Civ.P. 46. The “special needs” cases bear little resemblance to the highly supervised process of obtaining a material witness warrant. Given the protections in § 3144, there is simply no need to inquire into the government’s “programmatic purpose,” and no case has ever so required.
Second, the majority’s “traditional” definition of “probable cause,” which limits probable cause to mean only probable cause to believe that the arrestee is guilty of wrongdoing, Maj. Op. at 966-67, reflects a fundamental misunderstanding of the Fourth Amendment. The validity of a police action under the Fourth Amendment turns not on the guilt or innocence of the arrestee, but on whether the government’s reasons for arresting the individual are weighty enough, and probably factually likely enough, to justify the intrusion into some individual’s rights.7 See United States v. Knights, 534 U.S. 112, 118-19, 122 S.Ct. 587, 151 L.Ed.2d 497 (2001) (“The touchstone of the Fourth Amendment is reasonableness, and the reasonableness of a search is determined by assessing, on the one hand, the degree to which it intrudes upon an individual’s privacy and, on the other, the degree to which it is needed for the promotion of legitimate governmental interests.”) (internal quotation marks omitted). The “probable cause” requirement assures that there is sufficient evidence to believe that the facts that justify the issuance of the warrant exist — that there is a sufficient “probability” the government will find what it is looking for when it intrudes. Id. at 121, 122 S.Ct. 587.
Until today, no case has suggested that the only governmental interest of sufficient weight to justify an arrest is a reasonable belief that the arrestee has committed a crime. Most importantly, the Supreme Court has stated that the government’s interest in the integrity of the justice system is important enough to justify the arrest of a wholly innocent person to secure that witness’s appearance at trial. See Stein v. New York, 346 U.S. 156, 184, 73 S.Ct. 1077, 97 L.Ed. 1522 (1953) (“The duty to disclose knowledge of crime rests upon all citizens. It is so vital that one known to be innocent may be detained, in the absence of bail, as a material witness.”), rev’d on other grounds by Jackson v. Denno, 378 U.S. 368, 84 S.Ct. 1774, 12 L.Ed.2d 908 (1964); Barry v. United States ex rel. Cunningham, 279 U.S. 597, 616-17, 49 S.Ct. 452, 73 L.Ed. 867 (1929) (“The constitutionality of [the material witness statute] apparently has never been doubted.”).8 Our own jurisprudence, too, *988has recognized that “probable cause” for an arrest may exist even in the absence of a reasonable belief that the arrestee has committed wrongdoing. For example, police officers may arrest individuals innocent of any crime if the officer has reason to believe that the individual is a danger to himself. Maag v. Wessler, 960 F.2d 773, 776 (9th Cir.1992). To be sure, in the great run of arrest cases, the relevant inquiry will be whether officers had probable cause to believe the subject committed wrongdoing. But none of the cases the majority claims defines probable cause had occasion to consider whether such belief was the only belief that could justify an arrest.
In the closely analogous context of searches, it is clear that, consistent with the Fourth Amendment, government agents, with a warrant supported by probable cause, may intrude to search upon the premises even of individuals who are suspected of no wrongdoing whatsoever. In Zurcher v. Stanford Daily, 436 U.S. 547, 98 S.Ct. 1970, 56 L.Ed.2d 525 (1978), government agents obtained a warrant to search the offices of the Stanford Daily for photographs that might reveal the identity of protesters who had assaulted policemen during a campus disturbance. Id. at 548, 98 S.Ct. 1970. There was no claim that Stanford Daily photographers or employees were themselves the assailants. See id. The Supreme Court held the warrant was valid, despite the fact that members of the Stanford Daily were not suspected of having done anything wrong: “[Vjalid warrants may be issued to search any property, whether or not occupied by a third party, at which there is probable cause to believe that fruits, instrumentalities, or evidence of a crime will be found.” Id. at 554, 98 S.Ct. 1970 (emphasis added); see also Steagald v. United States, 451 U.S. 204, 101 S.Ct. 1642, 68 L.Ed.2d 38 (1981) (holding that an arrest warrant does not authorize officers to enter the homes of third parties to execute the warrant, absent exigent circumstances, without first obtaining a warrant to enter the premises).9
Though Zurcher involved a search, rather than a seizure, its rationale is applicable here and squarely rejects the majority’s contention that the probable cause requirement of the Fourth Amendment may be satisfied only by suspicion of wrongdoing by the subject of the intrusion. As the Supreme Court explained, the property owner’s guilt or innocence is simply irrele*989vant to the constitutional analysis: “it is apparent that whether the third-party occupant is suspect or not, the State’s interest in enforcing the criminal law and recovering the evidence remains the same.... ” Zurcher, 436 U.S. at 560, 98 S.Ct. 1970. And one who knows he has evidence relevant to a criminal prosecution but refuses to hand such evidence over to prosecutors “is sufficiently culpable to justify the issuance of a search warrant.” Id. The same holds true for a material witness. The government’s interest in recovery of evidence from a material witness is the same whether the witness is guilty or innocent of wrongdoing. The need to obtain evidence from that witness and secure his appearance at trial is of sufficient weight to justify an arrest. See Stein, 346 U.S. at 184, 73 S.Ct. 1077; Barry, 279 U.S. at 616-17, 49 S.Ct. 452.
In short, our cases, and those of the Supreme Court, have routinely recognized that “probable cause,” within the meaning of the Fourth Amendment, may be satisfied by proof of something other than wrongdoing by the subject of the search or seizure.
Of course, taken to its logical conclusion, the majority opinion renders the material witness statute entirely superfluous. To arrest and confine an individual pursuant to the material witness statute, the government must establish “probable cause.” Bacon, 449 F.2d at 941-43. If “probable cause” exists only when the subject of an arrest is suspected of a crime, then a material witness can be arrested as a suspect, and the material witness statute adds nothing.10 This result is risible.11
Once the government demonstrated to a neutral magistrate that it had probable cause to believe al-Kidd had information material to a criminal proceeding and was likely to run off to Saudi Arabia, the Whren rule applied with full force, and nothing in Edmond or any case the majority cites suggests otherwise.
Third, the Supreme Court’s decision in United States v. Villamonte-Marquez, 462 U.S. 579, 103 S.Ct. 2573, 77 L.Ed.2d 22 (1983), which the majority inadequately ad*990dresses, casts even greater doubt on the correctness of the majority’s decision. In that case, the Supreme Court authorized precisely what the majority says can never be permissible: a pretextual seizure in the absence of reasonable suspicion or probable cause. In that case, customs agents, acting on a tip about marijuana smuggling, detained a sailboat pursuant to 19 U.S.C. § 1581(a). That statute authorized customs agents to “board any vessel at any time and at any place in the United States to examine the vessel’s manifest and other documents.” Id. at 580, 103 S.Ct. 2573. While executing the document inspection, officers smelled marijuana. They found 5800 pounds of the stuff on board the ship and arrested the crew. Id. at 583, 103 S.Ct. 2573. The crew members were convicted for conspiracy to import marijuana. Id. On appeal, the Fifth Circuit reversed the convictions, holding the detention was invalid — the officers lacked constitutionally sufficient individualized suspicion of wrongdoing — and the fruits of the detention were barred from evidence. Id. at 583-84, 103 S.Ct. 2573. The Supreme Court reversed the decision of the Fifth Circuit and upheld the convictions. Id. at 584, 103 S.Ct. 2573. The Court held that the special difficulties associated with enforcement of maritime registration laws justified suspicionless stops and inspections on waterways. Id. at 591, 103 S.Ct. 2573. The Court emphasized the long historical pedigree of § 1581(a) as proof that the Founders did not believe such intrusions violated the Fourth Amendment. Id. at 584-85, 103 S.Ct. 2573. In a footnote, the Court rejected the crew members’ contention that the customs officers’ subjective intentions rendered the stop and inspection pretextual and thus unlawful:
Respondents, however, contend ... that because the Customs officers were accompanied by a Louisiana State Policeman, and were following an informant’s tip that a vessel in the ship channel was thought to be carrying marijuana, they may not rely on the statute authorizing boarding or inspection of the vessel’s documentation. This line of reasoning was rejected in a similar situation in Scott ... and we again reject it.
Id. at 584 n. 3,103 S.Ct. 2573.
Like the statute at issue in VillamonteMarquez, some version of the material witness statute has been on the books since the late-1700s. See Bacon, 449 F.2d at 938-41. Since then, courts have approved the constitutionality of the power to detain material witnesses. See supra note 11. As the Supreme Court explained, the “ ‘duty to disclose knowledge of crime ... is so vital that one known to be innocent may be detained, in the absence of bail, as a material witness.’ ” Bacon, 449 F.2d at 939 (quoting Stein, 346 U.S. at 184, 73 S.Ct. 1077).
Finally, Villamonte-Marquez also underlines the point that, even assuming we must consider the “programmatic purpose” behind al-Kidd’s detention, the relevant inquiry is not into the motivations of individual officers who obtained and executed the particular warrant on which al-Kidd was detained, but into the “programmatic purpose” that provides the constitutional justification for the material witness statute. See Edmond, 531 U.S. at 47, 121 S.Ct. 447 (“[W]e caution that the purpose inquiry in this context is to be conducted only at the programmatic level and is not an invitation to probe the minds of individual officers acting at the scene.”). The justification for the use of material witness warrants is the need to assure the proper functioning of the judicial system; this interest is divorced from the government’s general interest in crime control and is sufficient, alKidd concedes, to justify an arrest. Because this governmental interest justifies *991this intrusion into al-Kidd’s liberty, and because the intrusion is subject to a warrant requirement, inquiry into the minds of individual officers is neither necessary nor desirable. See Villamonte-Marquez, 462 U.S. at 584 n. 3, 103 S.Ct. 2573.
But even if al-Kidd’s arrest on a pretextual material witness warrant violated his Fourth Amendment constitutional right not to be subjected to an unreasonable seizure, any such right was certainly not “clearly established” in March 2003. As the majority notes, for a right to be clearly established there need not be a case on point, but the violation must be “apparent” to a reasonable official. Hope v. Pelzer, 536 U.S. 730, 739, 122 S.Ct. 2508, 153 L.Ed.2d 666 (2002). In March 2003, when al-Kidd was arrested on a material witness warrant, it would hardly have been “apparent” to a reasonable official that using a valid material witness warrant as a pretext to accomplish other law-enforcement objectives was constitutionally impermissible, especially if the official had read Whren, Robinson, Scott, or Macon.
No court had ever questioned the constitutional validity of the material witness statute. No court had ever held that the “programmatic purpose” test applied to searches or seizures conducted pursuant to a warrant. No court had held that “probable cause” in the Fourth Amendment meant only probable cause to believe the subject of the search or seizure had committed criminal wrongdoing. Every pronouncement by the Supreme Court would have suggested that the pretextual use of a valid warrant was perfectly legal.
Eight months after al-Kidd’s arrest, for the very first time, and in dicta no less, a court of appeals stated that the pretextual use of material witness warrants was “improper.” United States v. Awadallah, 349 F.3d 42, 59 (2d Cir.2003) (“The district court noted (and we agree) that it would be improper for the government to use § 3144 for other ends, such, as the detention of persons suspected of criminal activity for which probable cause has not yet been established.”).12 Prior to that, only cme district court had said anything similar. See United States v. Awadallah, 202 F.Supp.2d 55, 78 (S.D.N.Y.2002), rev’d on other grounds by Awadallah, 349 F.3d 42-In light of the substantial contrary authority spelling out that an officer’s subjective intentions do not invalidate an objectively valid warrant, this solitary district court decision was hardly sufficient to make it “apparent” to a reasonable official that the pretextual use of material witness warrants was unconstitutional. See Sorrels v. McKee, 290 F.3d 965, 970-71 (9th Cir.2002) (holding that two district court decisions were insufficient to make a right “clearly established”).
The Supreme Court has flatly stated that pretextual searches and seizures conducted pursuant to a warrant issued upon objectively reasonable probable cause do not violate the Fourth Amendment. Nothing in the majority opinion provides any justification for departing from this rule. Attorney General Ashcroft is entitled to qualified immunity.
*992III. Al-Kidd’s complaint fails to allege Ashcroft instructed or knowingly allowed FBI agents to present false affidavits to the magistrate judge who issued the material witness warrant.
Al-Kidd’s remaining claim is that Ashcroft is personally liable for al-Kidd’s detention on a material witness warrant’ obtained on the basis of intentional or reckless material misrepresentations or omissions. Of course, this claim raises totally different constitutional issues-than that based on pretext.
It is not disputed that al-Kidd has a clearly established constitutional right not to be detained on a warrant based on an agent’s deliberate or reckless misrepresentations or omissions. See Franks v. Delaware, 438 U.S. 154, 164-72, 98 S.Ct. 2674, 57 L.Ed.2d 667 (1978). But it was Ashcroft’s subordinates, not Ashcroft himself, who obtained the material witness warrant on which al-Kidd was detained. Al-Kidd makes only conclusory allegations Ashcroft ordered his subordinates to arrest individuals on invalid warrants. But such conclusory allegations do not suffice. Before we reach the merits of al-Kidd’s claims the affidavits were false, we must determine if he alleges facts sufficient to establish Ashcroft’s personal liability. I disagree with the majority’s conclusion that Ashcroft may be held liable for what his subordinates may have done here, because alKidd’s complaint simply does not state facts that plausibly establish Ashcroft, “through [his] own actions,” violated alKidd’s rights under the material witness warrant statute or the Constitution. Iqbal, 129 S.Ct. at 1948.
The majority concludes Ashcroft may be held liable in al-Kidd’s Bivens action for his “knowing failure to act” in the light of evidence of unauthorized abuses, and that al-Kidd’s pleadings are sufficient to establish plausibly that Ashcroft had knowledge of “abuses” occurring under § 3144 and failed to act to correct these abuses.13 Maj. Op. at 975-76.
What “abuses”? The abuses to which al-Kidd refers in his allegations are not lies or omissions included in supporting affidavits, but pretextual arrests. But, as shown above (in Part II, “Qualified Immunity”), such “abuses” violate neither the statute nor the Constitution. And to allege Ashcroft’s knowledge of these “abuses” does not allege facts that plausibly establish Ashcroft knew of or encouraged his subordinates recklessly to disregard the truth in the preparation of supporting affidavits. See Franks, 438 U.S. at 164-72, 98 S.Ct. 2674.
In reviewing al-Kidd’s allegations regarding Ashcroft’s personal involvement, ask yourself after each one, “Did al-Kidd here allege facts that plausibly establish Ashcroft ordered or knowingly tolerated agents swearing to false facts in their affidavits?”:
*993• Ashcroft stated publicly that “[aggressive detention of lawbreakers and material witness warrants is vital to preventing, disrupting, or delaying new attacks.”
• A Justice Department policy memo stated that federal law enforcement personnel were to use “every available law enforcement tool” to arrest terror “suspects.” This included the use of “aggressive arrest and detention tactics.”
• One Justice Department official admitted that the material witness policy amounted to “preventive detention.”
• Other Justice Department officials admitted that material witness warrants were an important “investigative tool” whereby they could obtain “evidence” about the witness. Similarly, FBI Director Mueller stated that several “suspects” had been detained on material witness warrants.
• One news report stated that 50% of those detained on material witness warrants were never called to testify. One Justice Department official admitted that this statistic proved that material witness warrants were a “ruse” to detain suspects.
• “Abuses” occurring under the statute were “highly publicized” in the media.
• The department apologized to several individuals arrested on material witness warrants.
In each case, the answer to the question put is a flat “no.” These allegations certainly do suggest Ashcroft encouraged prosecutors to use valid material witness warrants as a means to accomplish other law-enforcement objectives. But none of the allegations contain facts that plausibly establish Ashcroft’s knowledge that his subordinates were obtaining material witness warrants on the basis of deliberately or reddessly false evidence or on facially invalid warrants. Some of al-Kidd’s allegations suggest precisely the opposite— that Justice Department officials were careful to ensure they had probable cause to- believe that- the targeted witness had information material to a criminal proceeding and was likely to flee before seeking a material witness warrant:
• David Nahmias, Counsel to the Assistant Attorney General, stated that when they were unable to charge a particular suspect, they “got enough information at least to make him a material witness.” ER 32 (emphasis added).
• Attorney General Alberto Gonzales, Ashcroft’s successor, stated that when the agency became interested in a subject, the agency would “consider” its options. ER 31.
Al-Kidd’s pleadings do establish that some material witnesses were detained who did not testify or did not prove to have material information. But these facts do not plausibly suggest federal agents employed intentional or reckless mendacity in swearing out false affidavits. Some witnesses’ testimony may not have been required because defendants took plea deals or prosecutors found other sources of information. In some cases, agents may simply have been wrong or may have acted “hastily” or negligently in conducting investigations. That does not amount to a Franks violation. See Franks, 438 U.S. at 165, 98 S.Ct. 2674. That the DOJ apologized to some detainees hardly suggests an admission of impropriety rather than simple error.
The majority also concludes al-Kidd has plausibly alleged that Ashcroft “purposely instructed his subordinates to bypass the plain reading of the statute.” Maj. Op. at 976. All of the allegations the majority cites in support of this proposition demonstrate Ashcroft “purposely instructed” his subordinates to use the statute pretextually, but not unlawfully. *994The majority doesn’t get it; al-Kidd must plead not only that Ashcroft had a “concerted strategy” or that Ashcroft used “enhanced” techniques, Maj. Op. at 977, but that such “concerted strategy” or “enhanced” techniques actually included the use of false affidavits or facially invalid warrants, not just the use of pretextual witness warrants. A “concerted strategy” or “enhanced” technique to “misuse” material witness warrants is not enough, unless such “misuse” includes the use of false affidavits, not just pretextual arrest warrants. And nothing in al-Kidd’s allegations plausibly suggests Ashcroft instructed, encouraged, or tolerated his subordinates to detain individuals as to whom there was no objective probable cause to arrest. It may be conceivable to al-Kidd that Ashcroft encouraged his subordinates to flout the requirements of § 3144, but al-Kidd’s allegations have not “nudged [his] claims across the line from conceivable to plausible.” Bell Atlantic Corp. v. Twombly, 550 U.S. 544, 570, 127 S.Ct. 1955, 167 L.Ed.2d 929 (2007).
Because al-Kidd has not pleaded adequately that Ashcroft, by his own actions, violated al-Kidd’s constitutional rights, I dissent from part B.4 of the majority opinion.
IV. Absolute Immunity
The remaining question is whether and to what extent Ashcroft enjoys absolute immunity for his alleged actions — and in-actions — related to the issuance of material witness warrants. As explained above, I conclude all of al-Kidd’s claims are preeluded on other grounds. Accordingly, were it up to me, I would not reach this question. However, because the majority addresses the issue, and because I think the majority’s “immediate purpose” test is difficult to define and apply, and is unsupported by case law, I will explain my disagreement.
In Imbler v. Pachtman, 424 U.S. 409, 96 S.Ct. 984, 47 L.Ed.2d 128 (1976), the Supreme Court held that a prosecutor enjoyed absolute immunity from suit by a former inmate, whose conviction had been set aside in collateral proceedings. The former inmate’s suit alleged that the prosecution had been commenced wrongfully, that the prosecutor had elicited false testimony on the stand, and that the prosecutor concealed exculpatory evidence from the defense, actions even more heinous than those alleged against Ashcroft by alKidd. Id. at 415-16, 96 S.Ct. 984. The court articulated two justifications for imposing an absolute bar to recovery: first, absolute prosecutorial immunity reflects the common law immunity of judges and juries, id. at 424, 96 S.Ct. 984;14 second, absolute immunity is necessary to avoid the “intolerable burdens” that damages claims by disgruntled criminal defendants would place on prosecutors, id. at 425-26, 96 S.Ct. 984. Absolute prosecutorial immunity obviously leaves some wrongs— grievous wrongs — unremedied, but the “balance of evils” nonetheless tilts in favor of absolute immunity; otherwise, prosecutors would live in constant fear that then-actions on behalf of the public would sub*995ject them to personal liability and possible poverty. Van de Kamp v. Goldstein, — U.S.-, 129 S.Ct. 855, 859, 172 L.Ed.2d 706 (2009).
However, despite the tremendous importance of absolute immunity, prosecutors do not enjoy absolute immunity for every act they undertake as prosecutors. To determine whether a prosecutor enjoys absolute immunity, rather than the lesser qualified immunity afforded all government agents, courts consider the “the nature of the function performed, not the identity of the actor who performed it.” Kalina, 522 U.S. at 127, 118 S.Ct. 502. Under, the “functional approach,” a prosecutor enjoys prosecutorial immunity only when he performs a function “intimately associated with the judicial phase of the criminal process.” Imbler, 424 U.S. at 430, 96 S.Ct. 984. On the other hand, a prosecutor has no absolute immunity for “those aspects of the prosecutor’s responsibility that cast him in the role of an administrator or investigative officer pather than that of an advocate.” Id. at 430-31, 96 S.Ct. 984. The Imbler court acknowledged that “drawing a proper line between these functions may present difficult questions.” Id. at 431 n. 33, 96 S.Ct. 984.
Deciding which witnesses to call at trial is part of the prosecutor’s role as an advocate, Imbler, 424 U.S. at 431 n. 33, 96 S.Ct. 984, as is the “marshaling” of evidence for trial, Genzler v. Longanbach, 410 F.3d 630, 639 (9th Cir.2005). Accordingly, several eircuits, other than the Ninth, have squarely held that prosecutors have absolute immunity for seeking a material witness warrant.15 And no case has held that absolute immunity does not shield a prosecutor’s decision to seek such a warrant.
Ashcroft, of course, did not himself file the application or swear out the facts in support of the application'. Ashcroft acted only as a supervisor. Though a supervisor’s acts are in one sense always administrative, a supervisor enjoys absolute immunity only for supervisory decisions that “require legal knowledge and the exercise of related discretion” and relate to activities for which the supervised attorney enjoys absolute immunity. Van de Kamp, 129 S.Ct. at 861-62 (holding that a prosecutor enjoyed absolute immunity from Goldstein’s claims that, supervisor’s failure to train prosecutors about the need to disclose exculpatory evidence resulted in his unlawful conviction). There is “no meaningful distinction between a decision on prosecution in a single instance and decisions on prosecutions formulated as a policy for general application.” Roe v. City & County of San Francisco, 109 F.3d 578, 583-84 (9th Cir.1997).
Kalina v. Fletcher makes clear Ashcroft lacks absolute immunity for claims related to his supervision of the FBI agents, such as Mace, who acted as witnesses in support of a warrant application. See 522 U.S. at 129-30, 118 S.Ct. 502. When an individual, even an attorney, serves as a *996complaining witness in support of a warrant application, the individual enjoys only qualified immunity, id., and accordingly Ashcroft lacks absolute immunity for supervising such individuals. See Roe, 109 F.3d at 583-84. Whether Ashcroft enjoys absolute immunity for his supervision of the United States Attorneys who prepared the warrant application and made the decision to file it is a different question.
I would hold that so long as the “criminal proceeding” for which the material witness warrant is sought is a criminal trial, rather than an investigatory proceeding,16 the decision to seek a material witness warrant should be shielded by absolute immunity. Such a decision is clearly one “intimately associated with the judicial phase of the criminal process.” Imbler, 424 U.S. at 430, 96 S.Ct. 984; see also supra note 14. The critical factor in the decision to seek a material witness warrant is the prosecutor’s professional judgment about how much that witness knows, how important the witness’s testimony might be, and what effect his arrest may have on his testimony. See Kalina 522 U.S. at 130, 118 S.Ct. 502 (holding that absolute immunity protects decisions involving the “exercise of professional judgment”). And the ultimate decision whether to call the detained witness depends on the prosecutor’s final trial strategy, which may evolve over time as events unfold. See Roe, 109 F.3d at 583-84 (holding that a prosecutor’s decision not to call a witness at trial was protected by absolute immunity). Both of these decisions are decisions that only a prosecutor can make.
Moreover, like other quasi-judicial acts, an individual’s detention on a material witness warrant is subject to continuing oversight, and errors may be corrected through the judicial process. Cf. Mitchell, 472 U.S. at 522-23, 105 S.Ct. 2806 (holding that a prosecutor did not enjoy absolute immunity for his decision to engage in illegal wiretapping and explaining that the judicial process, unlike wiretapping, is “largely self-correcting: procedural rules, appeals, and the possibility of collateral challenges obviate the need for damages actions to prevent unjust results”).17 Here, Al-Kidd was not detained up until *997the start of trial, but was released upon conditions, selected by a neutral magistrate, thought necessary to secure his appearance as a witness at trial.
Ultimately, the decision whether to seek a material witness warrant in conjunction with an upcoming trial is akin to both the decision to call a witness at trial and to seek a warrant to arrest a suspect. A prosecutor enjoys absolute immunity for both of these acts, regardless of any improper motive, and should enjoy a similar immunity here. See Imbler, 424 U.S. at 431 n. 33, 96 S.Ct. 984; Kalina, 522 U.S. at 129, 118 S.Ct. 502.
Both the majority and al-Kidd concede that a prosecutor sometimes has absolute immunity for the decision to seek a material witness warrant. See Maj. Op. at 959-60. The majority, returning to its trope the prosecutors’ pretextual motivations invalidate an otherwise properly obtained warrant, see Maj. Op. at 962-63, contends, however, the cases holding a prosecutor has absolute immunity for the issuance of a material witness warrant — Odd, Betts, Daniels, and Swafford — are distinguishable because none involved allegations a prosecutor intended to use the warrant to investigate the detained subject rather than to secure the witness’s appearance at trial. See Maj. Op. at 959-60.18
Rejecting what it calls a “formalistic taxonomy of acts that are inherently either prosecutorial or investigative, regardless of what each act is really serving to accomplish” in favor of a “teleological perspective,” Maj. Op. at 962 (emphasis added), the majority applies an “immediate purpose” test to determine whether a prosecutor is performing an investigative rather than a prosecutorial function — if the prosecutor’s “immediate purpose” was to investigate the subject of the warrant rather than to secure the witness’s appearance at trial, the prosecutor enjoys only qualified, rather than absolute, immunity. Id. at 962-63. Again the majority invites inquiry into the subjective motivations of individual officers. One can tell that easily: watch for its use of the word “really.”
It is true that a few courts have made reference to “purpose” in applying the functional approach.19 But the “purpose” considered in these cases has been the product for which the warrant was directed — what evidence was called for and where it was to be produced; none of these cases authorizes the majority’s wide-ranging inquiry into what a prosecutor was “really” up to. See id. at 962-63. Indeed, as in the- Fourth Amendment context, courts have repeatedly admonished that a prosecutor’s subjective intentions are irrelevant to the absolute immunity inquiry, for much the same reason they are irrelevant to the qualified immunity analysis. See, e.g., Ashelman v. Pope, 793 F.2d 1072, *9981078 (9th Cir.1986) (en banc) (“Intent should play no role in the immunity analysis.”); see also Betts, 726 F.2d at 81 (2d Cir.1984) (“Absolute immunity attaches to [seeking a material witness warrant], and any claimed improper motive is irrelevant.”). The cases the majority cites are not to the contrary.
In Buckley, the Supreme Court held that a prosecutor lacked absolute immunity for fabricating evidence to present to a grand jury because the grand jury’s “immediate purpose was to conduct a more thorough investigation of the crime — not to return an indictment against a suspect against whom there was already probable cause to arrest.” 509 U.S. at 274-75, 113 S.Ct. 2606. Buckley simply reflects the general rule that a prosecutor should not “consider himself to be an advocate before he has probable cause to have anyone arrested.” Id. at 274, 113 S.Ct. 2606. In Buckley, no one had been arrested; the grand jury was still investigating. Here, Al-Hussayen had been indicted, arrested, arraigned, and was awaiting trial. Buckley merely holds that a prosecutor who, as yet, had arrested no one, was acting as an investigator, not an advocate. Buckley does not hold that what “really” motivated a prosecutor is relevant to determination of what “function” the prosecutor was accomplishing when he performed the action complained of.
Neither does KRL v. Moore. In that case, we held that whether a prosecutor had absolute immunity for the issuance of a search warrant depended on the purpose of the warrant, not of the prosecutor in seeking the warrant. 384 F.3d at 1115. After executing a search warrant on land held by KRL, a general partnership, prosecutors indicted Robert Womack, one of the partners, on counts relating to improper waste disposal on partnership land. Id. at 1108. The prosecutor then obtained a second search warrant for documents related to fraud and illegal diversion of funds. Id. at 1109, 1113. The partnership and the partners sued under § 1983, alleging that this second search warrant was overbroad, facially invalid, and based on fraudulent affidavits. Id. The district court denied the prosecutor’s absolute immunity claim. On appeal, this court noted that the second search warrant had “two goals: it sought evidence to prosecute the pending indictment against Womack, and it sought to investigate and uncover new crimes.” Id. at 1111. We held that the prosecutor enjoyed absolute immunity for the search warrant to the extent it sought evidence to prove the pending charges. Id. at 1111-13. However, to the extent the prosecutor sought evidence of new crimes (fraud at KRL), the prosecutors lacked absolute immunity. Id. at 1113-14.
We did not inquire into the prosecutor’s motives in seeking the second search warrant. We inquired into the purpose of the warrant by looking to what evidence the search warrant recited it sought. That evidence was not possibly related to the prosecution of Womack, the one suspect who had been arrested, for illegally dumping toxic wastes; it was evidence of fraud and diversion of funds that had nothing to do with waste disposal. Id. at 1113. It does not take a mind-reader to determine that where the subject matter of the prosecution is illegal toxic waste disposal on partnership land, a search warrant to search for evidence of fraud and illegal diversion of business funds is designed to accomplish something other than proving the elements of the charged environmental crime. It merely requires reading the warrant.
Buckley and ERL are easy to apply here: if the material witness warrant on which al-Kidd had been detained sought to force his appearance at an investigatory proceeding or a police interview, rather *999than a criminal trial, Ashcroft would not enjoy absolute prosecutorial immunity. The only relevant “purpose” is that derived from the product of the warrant, not what was “really” the prosecutor’s motive in seeking the warrant.
To the extent that KRL authorizes any inquiry into what was “really” the prosecutor’s motivation, such an inquiry should be strictly limited to cases where a prosecutor approves a search warrant application, because seeking the issuance of a search warrant can be an investigative function, while seeking an arrest warrant cannot. The KRL court itself carefully limited its holding to the search warrant context, and expressly distinguished the arrest warrant context. Id. at 1113 (“We must emphasize that our result would not necessarily be the same had the prosecutors reviewed an arrest warrant, rather than a search warrant, prior to submission. As noted supra, the Court has stated that a prosecutor does not serve as an advocate before probable cause to arrest anyone has been established, Buckley ..., but that the determination of whether probable cause exists to file charging documents is the function of an advocate.... ”). Preparing a search warrant is not a “core” advocacy function like the preparation of an arrest warrant, the filing of charges, or the preparation of a material witness warrant.20
But under the majority’s approach, what was “really” a prosecutor’s personal, subjective “immediate purpose” is always relevant to the determination whether absolute immunity protects any act by a prosecutor — in court or out of court. A prosecutor would lose his absolute immunity if he prosecutes a low-level mafia functionary for the sole purpose of inducing that functionary to testify against his capo. And, absolute immunity would not clothe any question asked by a prosecutor of a witness on the stand; the prosecutor could be sued for damages on the claim he “really” asked the question to assist in the investigation of the witness, or some other person, for other crimes. Of course, what the prosecutor “really” intended in asking the question would — as in all inquiries into intent — be a factual inquiry, entailing precisely the kind of expensive discovery and litigation immunity was designed to avoid. See Harlow, 457 U.S. at 816-817, 102 S.Ct. 2727.
Not so, says the majority. To “cabin” this obviously problematic result, the majority states that when a prosecutor brings any prosecution, the prosecutor’s “immediate purpose” is, of course, to bring a prosecution, even if the prosecutor’s true intention is to obtain evidence for some other investigation. Maj. Op. at 962-63. But there is no principled reason this is true, other than the majority’s say-so. And, if true, why isn’t the prosecutor’s “immediate purpose” in this case to secure a witness’s appearance at trial rather than to obtain evidence against al-Kidd? The majority provides no clues as to how we are to distinguish which purposes are “immediate” and which are “really” not.
*1000Even were the “immediate purpose” test coherent, it would nonetheless be undesirable because of the incentives it creates. The prosecutors’ ultimate decision not to call al-Kidd to the stand features prominently in al-Kidd’s proof that their “immediate purpose” was not to obtain a conviction against Al-Hussayen. Subjecting prosecutors to liability for such a decision risks needless interference in the prosecutor’s conduct of his most public function: the presentation of evidence at trial and, indeed, deciding whether to have a trial at all. Worse, the majority’s test makes it prudent for a prosecutor to go to trial against a defendant simply to ensure that his actions in preparing for trial will not become subject to attack on the grounds they were “really” designed to accomplish some other goal.
V. Conclusion
The majority opinion closes with a quote from Blackstone. What Blackstone describes and condemns therein — the indefinite and secret detention of individuals accused of no crime in harsh conditions — is simply not a description of this case. Even the majority agrees that the harsh conditions of al-Kidd’s confinement are not before us because al-Kidd has not adequately pleaded John Ashcroft’s personal responsibility for such conditions. Al-Kidd’s confinement was neither indefinite nor in secret. He was detained on a warrant issued by a neutral magistrate. The duration of that confinement was subject to continuing judicial supervision. There is no allegation that al-Kidd was held incommunicado. Nor is there any allegation al-Kidd was somehow denied the right to petition for a writ of habeas corpus, a right that has long secured individuals’ freedom from the horrors Blackstone envisioned. We are not called upon to judge the constitutionality of the material witness statute. And we are not called upon to judge whether al-Kidd should be released, only whether he is entitled to proceed in his suit to recover money damages from the pocket of a cabinet-level official. Were we presented with the Blackstonian case the majority envisions, I would surely agree.21 But we are not, and for the reasons explained above, I dissent in part and concur in part.
. As the majority states, the Al-Hussayen indictment alleged that one of the IANA’s purposes was "indoctrination, recruitment of members, and the instigation of acts of violence and terrorism.” The Al-Hussayen indictment also alleged Al-Hussayen himself was the sole registrant of another website, www.alasr.ws, which was affiliated with the IANA’s website through a third website belonging to the IANA. The www.alasr.ws website published an article in June 2001 entitled "Provision of Suicide Operations,” which advocated suicide bombings and "bringing down” aircraft.
. I express no opinion as to parts B.l ("Qualified Immunity Generally”) and B.2 ("Qualified Immunity for Supervisors”). I also express no opinion as to part C ("Personal Jurisdiction”). Because I conclude alKidd cannot proceed on his claims against Ashcroft, I would not reach the difficult question whether this court has pendent appellate jurisdiction over Ashcroft’s appeal of the district court's order denying his motion to dismiss al-Kidd's claims against him for lack of personal jurisdiction. If it is not necessary to decide an issue, it is necessary for a common-law court not to decide it.
. Al-Kidd later makes this claim separate and distinct from his pretext claim. It is addressed infra, parts III and IV.
. In Macon, an undercover police officer purchased pornographic materials from a bookstore. The officer left the bookstore, consulted with fellow officers, and, upon concluding the book was pornographic, returned to the bookstore and arrested the storekeeper and seized the marked bill the officer used to purchase the book. The Supreme Court held that the purchase, in a voluntary transaction, of wares by an undercover officer is not a search within the meaning of the Fourth Amendment. Id. at 469, 105 S.Ct. 2778. The storekeeper contended the officer’s subjective intention to retrieve the marked $50 bill transformed the sale into a search. Id. at 469-70, 105 S.Ct. 2778. The Supreme Court disagreed and held that because the transaction, objectively viewed, was a sale in the ordinary course of business, the sale, did not constitute a search. Id.
. In Scott, officers obtained a warrant to intercept the phone calls of a suspected drug dealer. Id. at 131, 98 S.Ct. 1717. The warrant required the officers to minimize their interception of non-narcotics-related phone calls. Id. The wiretap resulted in the arrest and indictment of more than twenty individu*985als. Id. Scott moved to suppress the intercepted phone calls on the ground officers had failed to comply with the minimization requirement. Id. at 132, 98 S.Ct. 1717. The district court granted the motion to suppress, concluding that even if evety intercepted phone call had been narcotics-related, the officers' failure to make any good faith efforts to comply with the minimization requirement rendered the wiretap illegal. Id. at 132-34, 98 S.Ct. 1717. The court of appeals reversed because the court could not conclude that reasonable efforts at minimization would have prevented the interception of any of the phone calls. Id. at 134, 98 S.Ct. 1717. After a jury trial on remand, Scott was convicted. The court of appeals affirmed, id. at 135, 98 S.Ct. 1717, and the Supreme Court affirmed the court of appeals. Id. at 137-38, 98 S.Ct. 1717. The Supreme Court rejected Scott’s contention that the officers’ “failure to make good-faith efforts to comply with the minimization requirement is itself a violation of [the wiretap statute].’’ Id. at 135, 98 S.Ct. 1717. The Court explained that the "existence vel non of such a violation turns on an objective assessment of the officer's actions in light of the facts and circumstances confronting him at the time,” not on the officers’s subjective intentions. Id. at 136, 98 S.Ct. 1717.
. For example, imagine two drug smugglers speeding, illegally, down the highway who are stopped by police. Each smuggler is identical in every respect, save one: one is stopped by an officer totally ignorant of the fact that the car is carrying drugs, the other by an officer who suspects the driver's involvement in a drug ring. Seen from the perspective of the two drivers, each should face an identical penalty. Each broke the law and made himself subject to being stopped. But if the suspicious officer's subjective intentions invalidate his stop, then one driver escapes punishment while the other does not. *986ks Devenpeck explained, an individual's right to be free of arrest should not depend upon such chance factors as which police officer arrested him. Id. at 155-56, 125 S.Ct. 588.
. This is not to deny the existence of what the majority terms the "substantive component” of the Fourth Amendment. Maj. Op. at 967. Instead, this merely demonstrates that this "substantive component” of the Fourth Amendment can be satisfied by any governmental interest — whether to detain a wrongdoer or to provide for the production of evidence against a wrongdoer — weighty enough to justify an intrusion into individual rights.
. The majority needlessly casts doubt upon the validity of § 3144. Even if the Supreme Court’s statements on the issue are dicta, they *988have considerable weight here. In part because we cannot “lightly” disregard any Supreme Court precedent, Siskiyou Regional Bduc. Project v. U.S. Forest Serv., 565 F.3d 545, 549 n. 1 (9th Cir.2009), and in part because this court has already positively commented on these statements, see Bacon, 449 F.2d at 941. In any event, al-Kidd does not contend that a showing of probable cause to believe (1) that a witness has information that is material in any criminal proceeding and (2) the witness's appearance cannot be secured by subpoena is insufficient to provide objective justification for an arrest. See Appellee’s Brief at 43. Notably, in neither Barry nor Stein was there any suggestion that the validity of a material witness warrant would either turn on the subjective intentions of the officers or depend upon a demonstration that there was probable cause to believe the subject of the arrest was guilty of wrongdoing.
. Steagald also demonstrates that the majority's invocation of the Wilkes cases is inapposite. The evil associated with the general writs and writs of assistance used in the colonial period was that these warrants "provided no judicial check on the determination of the executing officials that the evidence available justified an intrusion into a particular home.” Id. at 220, 101 S.Ct. 1642. § 3144 provides precisely the check on official discretion that was absent during the colonial period: supervision by a neutral magistrate. It was not Lord Halifax or even Attorney General Ashcroft who signed the material witness warrant that authorized al-Kidd’s arrest. It was a federal magistrate judge.
. The majority contends it does not render the material witness statute superfluous by arguing that if the statute is "genuinely” used to secure the testimony of a witness at trial, a showing of probable cause that the arrestee has engaged in wrongdoing is not required, and that only when the statute is being used as a pretext for criminal investigation is a showing of probable cause "including individualized suspicion of criminal wrongdoing ” required. Maj. Op. at 988-89. (emphasis in original). This argument suggests that the probable cause standard for issuing a warrant can vary depending on the subjective intention of the officer seeking the warrant. Not only is there no support in the case law for such a position, it is directly contradicted by the holding in Whren. 517 U.S. at 811, 116 S.Ct. 1769. Furthermore, the majority seems implicitly to recognize that probable cause can encompass more than the likelihood that the arrestee has engaged in criminal wrongdoing. Otherwise the majority's argument reads the necessity of showing probable cause right out of the issuance of a material witness warrant when the prosecutor "really” wants to obtain evidence for trial, and thus runs directly against the express language of the Fourth Amendment If the prosecutor wants a material witness warrant because he "really” wants to secure that person’s testimony at trial, according to the majority, he need not show probable cause that the potential witness engaged in wrongdoing. However, unless the majority also recognizes that probable cause in this context means showing a likelihood that the arrestee has material testimony, and that it will become impracticable to secure his presence by subpoena as required by 18 U.S.C. § 3144, then the majority would be sanctioning the issuance of an arrest warrant without any probable cause whatsoever.
. And we have been wasting much printer’s ink on material witness statutes which have existed at least since the late Eighteenth Century. See Bacon, 449 F.2d at 938-41.
. Obviously, we are not bound by the decision of another circuit, especially if that part of the decision was dicta. In any event, unlike in our circuit, dicta in the Second Circuit is not binding authority even in the Second Circuit. Jimenez v. Walker, 458 F.3d 130, 142-43 (2d Cir.2006). It also remains to be said: what did Awadallah mean by the use of “improper''? It could mean anything from pecksniffian distaste to sanctionable conduct by an officer of the courts, and from harmless error to grounds for reversal. It seems not even a thin reed upon which to base an assertion it proclaimed to the nation’s constabulary a "clearly established” constitutional right.
. Ashcroft cannot be held liable for the acts of his subordinates on a theory of respondeat superior or vicarious liability. Id. at 1948. It is doubtful that the majority’s "knowing failure to act" standard survived Iqbal. There, the Court held that Ashcroft could not be held liable for his "knowledge and acquiescence” in his subordinates’ alleged unconstitutional discrimination against Muslim men after 9/11. Id. at 1949. The Court explained: "[P]urpose rather than knowledge is required to impose Bivens liability on the subordinate for unconstitutional discrimination; the same holds true for an official charged with violations arising from his or her superintendent responsibilities." Id. at 1949. Here, because al-Kidd has not alleged that Ashcroft knew his subordinates were making deliberate or reckless material misrepresentations or omissions in material witness applications, much less that it was Ashcroft’s purpose they do so, alKidd’s allegations clearly fail Iqbal's requirements.
. Justice Scalia has observed that the doctrine of absolute prosecutorial immunity has strayed far from its common law roots, but that the doctrine nonetheless retains its vitality. See Kalina v. Fletcher, 522 U.S. 118, 131— 135, 118 S.Ct. 502, 139 L.Ed.2d 471 (1997) (Scalia, J., concurring) ("[T]he ‘functional categories’ approach to immunity questions imposed by cases like Briscoe, make faithful adherence to the common law embodied in § 1983 very difficult. But both Imbler and the ‘functional’ approach are so deeply embedded ... that, for reasons of stare decisis, I would not abandon them now.”). Accordingly, Ashcroft’s failure to introduce evidence that, at common law, prosecutors had absolute immunity against claims related to material witness warrants is not significant.
. See, e.g., Odd v. Malone, 538 F.3d 202, 213 (3rd Cir.2008) (noting that a prosecutor has prosecutorial immunity for obtaining a material witness warrant shortly before the commencement of trial, but holding that the prosecutor lacks absolute immunity for failing to notify the court that trial was over and thus permit the witness’s release); Betts v. Richard, 726 F.2d 79, 81 (2d Cir. 1984) ("It is clear that the issuance of the capias was intimately associated with procuring attendance of a witness for imminent trial. Absolute immunity attaches to this act, and any claimed improper motive is irrelevant.”); Daniels v. Kieser, 586 F.2d 64, 69 (7th Cir. 1978) ("Because defendant was attempting to secure Daniels’ presence at the resumption of the trial[,] ... he was functioning as an advocate rather than as an investigator.”); White ex rel. Swafford v. Gerbitz, 860 F.2d 661, 665 n. 4 (6th Cir. 1988) (stating, in dicta, that prosecutor’s decision to procure a material witness warrant is protected by absolute immunity).
. See Buckley v. Fitzsimmons, 509 U.S. 259, 274-75, 113 S.Ct. 2606, 125 L.Ed.2d 209 (1993) (holding that a prosecutor lacked absolute immunity for acts taken in preparation for appearing before an investigatory grand jury); see also Bacon, 449 F.2d at 939 (noting that a material witness warrant may issue to secure the presence of a witness before an investigative grand jury proceeding).
. The Third Circuit’s decision in Odd did not, as the majority concludes, hold that the policy considerations underlying absolute immunity do not apply in the material witness context. 538 F.3d 202. In Odd, no one questioned that the decision to seek a material witness warrant was protected by absolute immunity. The issue in Odd was the prosecutor's "fail[ure] to notify the court of the status of a detained witness.” Id. at 216. As the court noted, compliance with Rule 46, once trial is complete or during a "clearly delimited” break in judicial proceedings, is a purely ministerial task. Id. at 212-14. Unlike the decision whether to call a witness to the stand, the decision to release a material witness once trial is over requires the exercise of no professional judgment at all, and the threat of civil damages liability cannot interfere with the prosecutor’s decision making. Id. at 216. It is unsurprising that the Third Circuit found that the detained material witnesses lacked access to continuing supervision; in Odd the plaintiffs’ very claim was that they had been wrongfully denied the procedural protections to which they were entitled. Id. at 217 ("Indeed, the failure of the ADAs to notify anyone of Plaintiffs’ status assured that not even the warrant-issuing judges would review the propriety of their continued detention, thus short-circuiting the crucible of the judicial process.” (internal quotation marks omitted)). The ADAs had no more right to hold the material witness after the trial ended than they would have had to hold a defendant after an acquittal was entered.
. The odd result of the majority's approach is that Ashcroft enjoys absolute immunity if he acts out of racial or partisan animus, but enjoys only qualified immunity if he acts in order to protect the public or investigate a suspected criminal. See Bernard v. County of Suffolk, 356 F.3d 495, 504 (2nd Cir.2004). Thus, the more licit Ashcroft’s subjective intentions, the more liability he faces.
. See, e.g., Buckley, 509 U.S. at 274-75, 113 S.Ct. 2606 (holding that prosecutor lacked absolute immunity for actions before a grand jury because the grand jury's "immediate purpose was to conduct a more thorough investigation of the crime — not to return an indictment against a suspect against whom there was already probable cause to arrest”); KRL v. Moore, 384 F.3d 1105, 1115 (9th Cir.2004) (denying absolute immunity where a search warrant was ‘To further a ‘stand-alone investigation’ into environmental crimes”); Guzman-Rivera v. Rivera-Cruz, 55 F.3d 26, 30-31 (1st Cir. 1995) ("The mixed purpose of the civil rights investigation reflects defendants’ own mixed functions.”); Hill v. City of New York, 45 F.3d 653, 662 (2d Cir. 1995) ("To the extent that the creation of the videotapes fulfilled an investigatory purpose, Adago cannot claim absolute immunity.”).
. See generally Schrob v. Catterson 948 F.2d 1402, 1413-15 (3d Cir.1991) (distinguishing "core” prosecutorial functions and describing search warrants as in the "gray area” between investigative and prosecutorial functions); see also Joseph v. Patterson, 795 F.2d 549, 556-57 (6th Cir.1986) (recognizing that search warrants can serve both a prosecutorial function of preparing for trial and an investigative function of gathering evidence, and holding that further factual development was required to determine the role the search warrant played); Imbler, 424 U.S. at 431 n. 1, 96 S.Ct. 984 (“Preparation, both for the initiation of the criminal process and for a trial, may require the obtaining, reviewing, and evaluation of evidence. At some point, with respect to some decisions, the prosecutor no doubt functions as an administrator ....”) (emphasis added).
. Although I would distance myself from a certain measure of bristling righteousness in its remarks that al-Kidd was a U.S. citizen, married and with children at the time of his arrest. Maj. Op. at 951. For all of that, his rights under the Constitution against unlawful arrest were no greater than those of an illegally entered, Mexican, childless spinster.