[46] In her concurrence, Justice O'Connor explained that penalties severe enough to offend the Fifth Amendment privilege include: "termination of employment, [Uniformed Sanitation Men Ass'n, Inc. v. City of New York, 392 U.S. 280 (1968)], the loss of a professional license, [Spevack v. Klein, 385 U.S. 511 (1967)], ineligibility to receive government contracts, [Lefkowitz v. Turley, 414 U.S. 70 (1973)], and the loss of the right to participate in political associations and to hold public office, [Lefkowitz v. Cunningham, 431 U.S. 801 (1977)]." McKune, 536 U.S. at 49-50. In contrast, an inmate's "reduction in incentive level, and a corresponding transfer from a medium-security to a maximum-security part of the prison" were not "serious enough to compel him to be a witness against himself." Id. at 50.

[47] [5] Significantly, Justice O'Connor did not attempt to establish the governing standard for all cases, noting that she did not "need [to] resolve this dilemma [of setting forth a comprehensive theory of the self-incrimination privilege] to make [her] judgment in" McKune. Id. at 54. Nevertheless, though Justice O'Connor's concurrence does not delineate the limits of the self-incrimination clause's protections, it makes clear that the Court likely would conclude that the penalty Antelope faced for not participating in SABER was constitutionally impermissible.

[48] Although Justice O'Connor agreed with the plurality that Lile's "reduction in incentive level, and . . . corresponding transfer from a medium-security to a maximum-security part of the prison" were not penalties "sufficiently serious to compel his testimony," Justice O'Connor said that she "d[id] not agree with the suggestion in the plurality opinion that these penalties could permissibly rise to the level of . . . penalties [like] longer incarceration and execution [which] are far greater than those we have already held to constitute unconstitutional compulsion." Id. at 50, 52. Justice O'Connor did not accept the plurality's reasoning that the different outcomes in the "penalty cases" and the Court's decisions in cases like Murphy and Woodard could be explained on the basis of the citizen-prisoner distinction and that the key factor in assessing a prisoner's self-incrimination claim was whether the disputed penalty, in the plurality's language, amounted to an "atypical and significant hardship" within the prison context. Justice O'Connor explained:

[49] I believe the proper theory should recognize that it is generally acceptable to impose the risk of punishment, however great, so long as the actual imposition of such punishment is accomplished through a fair criminal process. . . . Forcing defendants to accept such consequences seems to me very different from imposing penalties for the refusal to incriminate oneself that go beyond the criminal process and appear, starkly, as government attempts to compel testimony

[50] Id. at 53 (internal citation omitted).

[51] Thus, under Justice O'Connor's opinion in McKune, the compulsion inquiry does not dispositively turn on the status of the person claiming the Fifth Amendment privilege or on the severity of the penalty imposed, although these factors may bear on the analysis. Instead, the controlling issue is the state's purpose in imposing the penalty: Although it may be acceptable for the state to impose harsh penalties on defendants when it has legitimate reasons for doing so consistent with their conviction for their crimes of incarceration, it is a different thing to impose "penalties for the refusal to incriminate oneself that go beyond the criminal process and appear, starkly, as government attempts to compel testimony." Id.

[52] Applying these principles here, we reject that the state could sanction Antelope for his self-protective silence about conduct that might constitute other crimes. We do not doubt that SABER's policy of requiring convicted sex offenders to give a sexual history, admitting responsibility for past misconduct to participating counselors, serves an important rehabilitative purpose. See, e.g., id. at 33 (plurality opinion) ("An important component of [sex offender] rehabilitation programs requires participants to confront their past and accept responsibility for their misconduct. . . . Research indicates that offenders who deny all allegations of sexual abuse are three times more likely to fail in treatment than those who admit even partial complicity.") (citing U.S. Dep't of Justice, Nat'l Inst. of Corr., A Practitioner's Guide to Treating the Incarcerated Male Sex Offender 73 (1988) and B. Maletzky & K. McGovern, Treating the Sexual Offender 253-55 (1991)). Often sex offenders repeat their past offenses, and informed counseling can only help protect them, their potential victims, and society. The irreconcilable constitutional problem, however, is that even though the disclosures sought here may serve a valid rehabilitative purpose, they also may be starkly incriminating, and there is no disputing that the government may seek to use such disclosures for prosecutorial purposes. In fact, Antelope's SABER counselor testified that he routinely transmits to authorities any admissions his clients make about past sex crimes, and that such reports have led to more prosecutions and convictions. Cf. McKune, 536 U.S. at 40-41 (plurality opinion) (arguing that a "critical distinction" between McKune and the penalty cases where the Court found Fifth Amendment violations is that "[t]here is no indication that the SATP is an elaborate attempt to avoid the protections offered by the privilege against compelled self-incrimination").

[53] [6] Justice O'Connor made clear in her McKune concurrence that she would not have found a penalty of "longer incarceration" such as that here to be constitutionally permissible. Id. at 52. The strength of Justice O'Connor's opinion as precedent is reinforced because it seems certain that the four dissenters in McKune, who argued that a loss of discretionary privileges and a transfer to less desirable living quarters under similar circumstances were sufficiently compulsive to violate Lile's privilege against self-incrimination, would find a Fifth Amendment violation where the district court revoked Ante-lope's conditional liberty and sentenced him to an additional ten months in prison.*fn3 On the basis of McKune, we hold that Antelope's privilege against self-incrimination was violated because Antelope was sentenced to a longer prison term for refusing to comply with SABER's disclosure requirements.*fn4

[54] Our holding comports with the case authority in our sister circuits which suggests that the conditions must not only be sufficiently coercive, but also more than merely hypothetical. When probation and supervised release terms are at issue, a court must determine whether the alleged Fifth Amendment problem truly implicates the defendant's conditional liberty. In United States v. Lee, 315 F.3d 206, 212 (3d Cir. 2003), cert. denied, 540 U.S. 858 (2003), for example, the Third Circuit rejected a defendant's challenge to his supervised released condition because Lee offered "no evidence that [his] ability to remain on probation is conditional on his waiving the Fifth Amendment privilege with respect to future criminal prosecution." In Lee, the prosecutor had stipulated that Lee's failure "to pass a polygraph examination, in and of itself, likely would not result in a finding of a supervised release violation." Id. Without the real risk of revocation, the polygraph's effect on Lee could not amount to constitutional compulsion.

[55] The First Circuit likewise faced a Fifth Amendment challenge to a supervised release condition imposing a polygraph exam requirement in United States v. York, 357 F.3d 14 (1st Cir. 2004). The twist in York was an ambiguous provision in the release condition: "When submitting to a polygraph exam, the defendant does not give up his Fifth Amendment rights." Id. at 18. The First Circuit grappled with York's Fifth Amendment challenge, acknowledging that "the polygraph requirement may implicate York's Fifth Amendment rights, depending on how the district court's order is understood." Id. at 24. The York court carefully avoided interpreting the release condition to mean "that it flatly requires York to submit to polygraph testing as a condition of his supervised release, so that York's refusal to answer any question-even on valid Fifth Amendment grounds-could constitute a basis for revocation." Id. Rather than impute this "constitutionally problematic" meaning to the release condition, the First Circuit simply construed it to mean that "York's supervised release shall not be revoked based on his valid assertion of Fifth Amendment privilege during a polygraph examination." Id. at 24-25.

[56] Although the First and Third Circuits found an interpretative way around the Fifth Amendment issue, the path of constitutional avoidance taken in York and Lee is unavailable here. Whether Antelope's supervised release is actually conditioned on his participation in SABER is a question whose answer is certain. Antelope has already suffered repeated revocation of his conditional liberty as a result of invoking his Fifth Amendment right. And, we have no doubt that Ante-lope's loss of liberty was as "substantial" a penalty as, if not more serious than, the ones imposed upon the litigants in the line of cases from Spevack to Cunningham-and totally unlike the mere transfer from one part of a prison to another, as in McKune.

[57] [7] Here, the district court tried to walk a fine line between the government's absolutist view-that full disclosure without immunity was a condition of release-and Antelope's view- that full disclosure without Fifth Amendment protection was a no-win proposition. Although this effort was laudable and the district court was sensitive in recognizing Antelope's Catch-22 predicament, its ruling left Antelope in legal limbo. Ultimately, the district court revoked Antelope's supervised release as a result of his refusal to disclose his sexual history without receiving immunity from prosecution. Because the government and district court have consistently refused to "recognize[ ] that the required answers may not be used in a criminal proceeding" against Antelope, Murphy, 465 U.S. at 435 n.7, we hold that the revocation of his probation and supervised release violated his Fifth Amendment right against self-incrimination.

[58] C. Antelope's Entitlement to Kastigar Immunity

[59] The nature of Antelope's entitlement to immunity for incriminating statements is subject to some dispute between the parties. We find it appropriate to resolve their disagreement because the issue is intimately bound up with the resolution of the merits of Antelope's Fifth Amendment claim. The government argues that Antelope has no entitlement to an assurance of immunity before he makes incriminating statements. See Kastigar, 406 U.S. at 453 (holding use and derivative use immunity under 18 U.S.C. §§ 6002-6003 co-extensive with the Fifth Amendment privilege). It contends, in effect, that the government has the right to compel Antelope to incriminate himself, prosecute him, and force him to litigate the admissibility of each piece of evidence in future criminal proceedings. Only then, according to its view, can Antelope properly assert his Fifth Amendment privilege. We disagree.

[60] As the Supreme Court has explained, adoption of the government's position would all but eviscerate the protections the self-incrimination clause was designed to provide. See, e.g., Turley, 414 U.S. at 78 ("[A] witness protected by the privilege may rightfully refuse to answer unless and until he is protected at least against the use of his compelled answers and evidence derived therefrom in any subsequent criminal case in which he is a defendant." (emphasis added)). More recently, Justice Thomas, speaking for four members of the Court, reaffirmed this principle: "By allowing a witness to insist on an immunity agreement before being compelled to give incriminating testimony in a non-criminal case, the privilege preserves the core Fifth Amendment right from invasion . . . ." Chavez v. Martinez, 538 U.S. 760, 771 (2003) (Thomas, J., in a plurality opinion joined by Rehnquist, C.J., O'Connor, J., and Scalia, J.) (emphasis in original).

[61] That this protection should be the law is only logical; "the failure to assert the privilege will often forfeit the right to exclude the evidence in a subsequent 'criminal case.' " Id. (citing Murphy, 465 U.S. at 440). Without a pre-testimonial assurance of immunity, the witness would scarcely be better protected than if there were no privilege at all. See id. ("If the privilege could not be asserted [before making the incriminating disclosure], testimony given in those judicial proceedings would be deemed 'voluntary' . . . ." ). Our conclusion in this case gives effect to Justice Thomas's admonition that "it is necessary to allow assertion of the privilege prior to the commencement of a 'criminal case' to safeguard the core Fifth Amendment trial right." Id.

[62] In the face of the vast weight of precedent to the contrary, see, e.g., Murphy, 465 U.S. at 429-40 (discussing circumstances where the Fifth Amendment privilege is triggered the moment a defendant is compelled to give statements which might incriminate him in criminal proceedings, even if such proceedings have yet to be initiated), the government contends that Chavez stands for the proposition that Antelope may not assert the Fifth Amendment right until the moment a compelled statement is used in a criminal proceeding against him. But Chavez did not, as the government suggests, unseat decades of Supreme Court law. Instead, the govern-ment's argument reveals a fundamental misunderstanding of Chavez.

[63] Chavez was a civil rights suit filed under 42 U.S.C. § 1983 by a plaintiff alleging that a police officer who aggressively questioned him violated his Fifth Amendment right. Six justices agreed with the defendant police officer that the cause of action premised on a Fifth Amendment violation could not survive summary judgment. See Chavez, 538 U.S. at 766-67 (Thomas, J., joined by Rehnquist, C.J., O'Connor, J., and Scalia, J.); id. at 777-79 (Souter, J., concurring, joined by Breyer, J.). But Chavez left unaltered the Court's commitment to safeguarding the Fifth Amendment's core guarantee under the circumstances presented here-a point the government chooses to ignore. Critical to the reasoning of all six justices was the simple principle that the scope of the Fifth Amend-ment's efficacy is narrower when used as a sword in a civil suit than when used as a shield against criminal prosecution. See id. at 772-73 (Thomas, J., joined by Rehnquist, C.J., O'Connor, J., and Scalia, J.) ("Rules designed to safeguard a constitutional right [such as that protected by the self-incrimination clause] do not extend the scope of the constitutional right itself . . . . Accordingly, Chavez's failure to read Miranda warnings to Martinez . . . cannot be grounds for a § 1983 action. And the absence of a 'criminal case' in which Martinez was compelled to be a 'witness' against himself defeats his core Fifth Amendment claim." (internal citations omitted)); id. at 777-78 (Souter, J., concurring, joined by Breyer, J.) (explaining that while case law "requiring a grant of immunity in advance of any testimonial proffer . . . . is outside the Fifth Amendment's core," the privilege's protections will only be expanded where "the core guarantee, or the judicial capacity to protect it, would be placed at some risk in the absence of such complementary protection," and concluding that it was not "necessary to expand protection of the privilege . . . to . . . civil liability"). Simply stated, the holding of Chavez is tightly bound to its § 1983 context.

[64] [8] Were Antelope to turn the tables and sue the government, Chavez would direct our inquiry to the "core constitutional right"-and, in such a posture, the government's argument might well prevail. But here, where Antelope is on the defensive, Fifth Amendment case law offers him protection beyond what the Chavez plurality called the "core" right. Thus, whether we describe our decision as arising out of a "prophylactic" or "constitutional" rule, the same result obtains: Antelope followed the appropriate course of action by refusing to answer the sexual history question until he was assured that his answers would be protected by immunity.*fn5

[65] III. THE PROHIBITION ON "ANY PORNOGRAPHIC MATERIALS"

[66] [9] Antelope also challenges as unconstitutionally vague the provision of his supervised release prohibiting him from possessing "any pornographic, sexually oriented or sexually stimulating materials." In United States v. Guagliardo, 278 F.3d 868 (9th Cir. 2002), we held impermissibly vague a similar supervised release term. Guagliardo was prohibited from possessing " 'any pornography,' including legal adult pornography." Id. at 872. Because "a probationer cannot reasonably understand what is encompassed by a blanket prohibition on 'pornography,' " we remanded for clarification. Id. We do the same here. The condition imposed on Antelope is indistinguishable from the one imposed on Guagliardo. Here, instead of "any pornography," we have "any pornographic . . . materials."

[67] The government contends that "sexually oriented or sexually stimulating" should be read to define "pornographic." We decline to adopt this grammatically unnatural reading. The release term explicitly lists three types of materials that Antelope may not possess: "any pornographic, sexually oriented or sexually stimulating materials." Because the condition imposed on Antelope suffers from the same defect as the one struck down in Guagliardo, we vacate and remand for clarification. Upon reconsideration, the district court may take note of the condition imposed in United States v. Rearden, 349 F.3d 608 (9th Cir. 2003), which passed constitutional muster.

[68] IV. THE PROHIBITION ON "ACCESS TO ANY ON-LINE COMPUTER SERVICE"

[69] Antelope's final argument challenges as overbroad the supervised release term prohibiting him from "possess[ing] or us[ing] a computer with access to any 'on-line computer service' at any location (including employment) without the prior written approval of the probation department."

[70] [10] As Antelope acknowledges, we recently rejected precisely such a challenge in Rearden. See id. at 620-21. He argues, however, that his case should be treated differently because his crime involved less use of the Internet and was less severe than Rearden's. Although there is some appeal to this nuance, the Internet was nevertheless essential to the commission of Antelope's crime: He first contacted the federal agents through joining a child pornography-oriented online group. Added to the evidence suggesting that Ante-lope's crime was one step on a path towards more serious transgressions, there is enough to justify the imposition of the term "to protect the public from further crimes of the defendant" and "to afford adequate deterrence to criminal conduct." 18 U.S.C. § 3553 (a)(2)(B) & (C). We affirm the imposition of this provision of Antelope's supervised release.

[71] CONCLUSION

[72] Accordingly, the decision of the district court revoking Antelope's supervised release because he invoked his Fifth Amendment rights in connection with the SABER program is REVERSED, the imposition of the release term prohibiting access to "any pornographic materials" is VACATED and REMANDED, and the release term prohibiting "access to any 'on-line computer service' " is AFFIRMED.


Opinion Footnotes

[73] *fn1 Abiding by the rule that when "no single rationale explaining the result enjoys the assent of five Justices, the holding of the Court may be viewed as that position taken by those Members who concurred in the judgments on the narrowest grounds," Marks v. United States, 430 U.S. 188, 193 (1977) (internal quotation marks omitted), we treat Justice O'Connor's opinion in McKune as controlling. Two of our sister circuits considering this question have arrived at the same conclusion. Ainsworth v. Stanley, 317 F.3d 1, 4 (1st Cir. 2002) ("Justice O'Connor's concurrence [in McKune] is arguably more narrow than the plurality's and therefore constitutes the holding of the Court.") (internal quotation marks omitted); Searcy v. Simmons, 299 F.3d 1220, 1225 (10th Cir. 2002) ("Because Justice O'Connor based her conclusion on the narrower ground that the [Kansas] policy was not compulsion under the Fifth Amendment, we view her concurrence as the holding of the Court in McKune.").

[74] *fn2 The SABER release form provides: "I hereby allow SABER to report to the appropriate authorities . . . any and all information concerning my behavior which is related to sexual offending."

[75] *fn3 Indeed, the McKune plurality, even with its more stringent standard, might here hold that the Fifth Amendment's self-incrimination clause was violated, given that the McKune plurality declared that Kansas had not used the information gathered in SATP for prosecutorial purposes, id. at 34, and that Lile's refusal to participate in Kansas's SATP did not result in an "exten[sion of] his term of incarceration." Id. at 38.

[76] *fn4 The Court's pre-McKune decision in Murphy is consistent. In Murphy the defendant challenged a condition of his probation requiring him to "be truthful with [his] probation officer 'in all matters' " or "return to the sentencing court for a probation revocation hearing," arguing that this condition unconstitutionally forced him to choose between making self-incriminating disclosures or returning to prison. 465 U.S. at 422. The Court held that there was no Fifth Amendment violation because the defendant "could not reasonably have feared that the assertion of the privilege would have led to revocation," given that the state would have provided a hearing before revocation, and defendant could have raised the privilege as a reason for noncompliance, and that the defendant could point to no case in which Minnesota revoked probation when a probationer "refused to make nonimmunized disclosures concerning his own criminal conduct." Id. at 439. The Court said that the outcome would have differed if the state "expressly or by implication, assert[ed] that invocation of the privilege would lead to revocation of probation," because this would have resulted in "the classic penalty situation." Id. at 435. Here we have the "classic penalty situation" contemplated in Murphy; Antelope's supervised release ended because he would not make potentially self-incriminating statements as required by SABER.

[77] *fn5 The scope of the immunity should be consistent with the Supreme Court's opinion in Kastigar, 406 U.S. at 453 (holding that "immunity from use and derivative use [provided by 18 U.S.C. §§ 6002-6003] is coextensive with the scope of the privilege against self-incrimination"). Kastigar, of course, does not insulate Antelope from prosecution altogether, just from the "use and derivative use" of compelled admissions in trial against him. Id.