                 FOR PUBLICATION
 UNITED STATES COURT OF APPEALS
      FOR THE NINTH CIRCUIT

UNITED STATES OF AMERICA,                  No. 03-30334
                Plaintiff-Appellee,
               v.                            D.C. No.
                                          CR-00-00039-DWM
LAWRENCE ANTELOPE,
             Defendant-Appellant.
                                      

UNITED STATES OF AMERICA,                  No. 03-30557
                Plaintiff-Appellee,
               v.                            D.C. No.
                                          CR-00-00039-DWM
LAWRENCE ANTELOPE,
                                              OPINION
           Defendant-Appellant.
                                      
       Appeal from the United States District Court
               for the District of Montana
       Donald W. Molloy, District Judge, Presiding

                  Argued and Submitted
            June 8, 2004—Seattle, Washington

                  Filed January 27, 2005

   Before: Melvin Brunetti, M. Margaret McKeown, and
            Ronald M. Gould, Circuit Judges.

               Opinion by Judge McKeown




                           1151
1154              UNITED STATES v. ANTELOPE


                         COUNSEL

Anthony R. Gallagher, Federal Defender, John Rhodes, Assis-
tant Federal Defender, and David Avery, Federal Defenders
of Montana, Missoula, Montana, for the defendant-appellant.

William W. Mercer, United States Attorney, Marcia Hurd,
Assistant United States Attorney, Billings, Montana, for the
plaintiff-appellee.


                         OPINION

McKEOWN, Circuit Judge:

   Lawrence Antelope is a convicted sex offender who shows
promise of rehabilitation. The terms of his supervised release
offer him treatment—but at a price he is not willing to pay.
Antelope has repeatedly refused to incriminate himself as part
of his sex offender treatment. He declines to detail his sexual
                   UNITED STATES v. ANTELOPE                1155
history in the absence of any assurance of immunity because
of the risk that he may reveal past crimes and that his admis-
sions could then be used to prosecute him. In response, the
government has twice revoked his conditional liberty and sent
him to prison. The case he now brings requires us to decide
whether the government’s actions violated his Fifth Amend-
ment right against compelled self-incrimination. Because the
Constitution does not countenance the sort of government
coercion imposed on Antelope, and because his claim is ripe
for adjudication, we reverse the judgment of the district court.

   We decide also Antelope’s challenge to the release term
prohibiting him from possessing “any pornographic, sexually
oriented or sexually stimulating materials,” which we vacate
and remand, as well as his challenge to the term prohibiting
him from access to “any ‘on-line computer service,’ ” which
we affirm.

                      BACKGROUND

  The course of events leading to this appeal began when
Lawrence Antelope joined an Internet site advertising “Pret-
een Nude Sex Pics” and started corresponding with someone
who, unbeknownst to Antelope, was an undercover law
enforcement agent. The sting operation proved fruitful when
Antelope ordered a child pornography video over the Internet.
Federal agents arranged a controlled delivery, delivered the
video, and then promptly arrested Antelope.

  Caught red-handed, Antelope pleaded guilty to possessing
child pornography in violation of 18 U.S.C. § 2252A(a)(5)(B)
and was initially sentenced to five years probation. One of the
probation terms required Antelope to participate in the Sexual
Abuse Behavior Evaluation and Recovery program
(“SABER”), which would subject him to mandatory “periodic
and random polygraph examinations.” At sentencing, Ante-
lope raised a Fifth Amendment challenge to this requirement,
but was told by the district judge that the “use of that informa-
1156               UNITED STATES v. ANTELOPE
tion . . . is, I think, subject to the privilege between the coun-
selor and the patient.” Antelope was also prohibited from
“possess[ing] any pornographic, sexually oriented or sexually
stimulating materials” and from “possess[ing] or us[ing] a
computer with access to any ‘on-line computer service’ at any
location . . . without the prior written approval of the proba-
tion department.” Both Antelope and the government
promptly appealed the sentence.

   While the appeal was pending, the district court revoked
Antelope’s probation for failure to comply with several proba-
tion conditions, including the requirement that he submit to
polygraph examinations as part of the treatment program. The
district judge re-imposed probation with an additional six
months of electronic monitoring and warned that Antelope’s
continued refusal to submit to the polygraph would result in
his incarceration. Antelope appealed this ruling as well.

   Immediately following this ruling, Antelope filed a motion
in the district court seeking to clarify whether the order
included immunity from the use of Antelope’s statements
made in compliance with SABER to prosecute him. The dis-
trict court never ruled on this motion, later dismissing it as
moot.

   While these appeals were pending, the district court again
found Antelope in violation of probation. At the probation
revocation hearing, Roger Dowty, Antelope’s counselor at the
sex treatment program, testified that Antelope had failed to
complete SABER’s sexual history autobiography assignment
and “full disclosure polygraph” verifying his “full sexual his-
tory.” Dowty explained that Antelope had been told that any
past criminal offenses he revealed in the course of the pro-
gram could be released to the authorities. Dowty also testified
that he was under a legal obligation to turn over information
regarding offenses involving victims under eighteen. Ante-
lope argued that the autobiography and full disclosure poly-
graph requirements violated his Fifth Amendment right,
                   UNITED STATES v. ANTELOPE                 1157
expressed his desire to continue treatment, and sought immu-
nity for statements made in compliance with the program. The
district court rejected his argument, ruling that the fact of pro-
bation nullifies any Fifth Amendment right Antelope might
otherwise have to decline to “reveal[ ] information that may
incriminate him,” and sentenced him to 30 months in prison.
Antelope appealed a third time.

  All three appeals were consolidated for appellate review,
and this court issued a decision reversing in part and remand-
ing for resentencing. The court declined to reach Antelope’s
First and Fifth Amendment claims. See United States v. Ante-
lope, 65 Fed. Appx. 112 (9th Cir. 2003) (mem.).

   Following remand, Antelope was resentenced to twenty
months incarceration, followed by three years of supervised
release. The district court again imposed the contested condi-
tions as terms of his supervised release. Antelope once again
objected, but the court ruled that the objection was not ripe,
and would not be ripe until Antelope was “prosecuted or sub-
ject to prosecution” for additional crimes. Antelope appealed
once more. This fourth appeal is one of the two directly
before us now.

   Shortly after he was resentenced, Antelope finished serving
his prison term and was released under supervision. Antelope
reasserted his desire for treatment but continued to refuse to
reveal his full sexual history absent an assurance of immunity.
When Antelope appeared at a release revocation hearing, he
yet again argued the merits of his Fifth Amendment claim.
The district judge reiterated his belief that Antelope’s admis-
sions would be protected by an “absolute privilege under
Montana law between a counselor, psychologist and the
patient”; asserted that “given the fact that [Antelope has] not
said anything yet, . . . everything is premature[ a]nd until this
judicial proceeding, where he’s compelled to testify, it seems
to me, . . . you don’t have any legal arguments to be making
that are meritorious in my view today”; and declined to rule
1158              UNITED STATES v. ANTELOPE
on whether Antelope’s admissions would be protected by use
immunity, apparently on ripeness grounds. The district judge
suggested that Antelope’s proper course would be to “assert[ ]
his privilege when he goes to see Mr. [Dowty, the counselor,]
and say[ ], I am doing this because I’m ordered to do it. I am
not doing it voluntarily, it’s a court order, and I do it only
because if I don’t do it I’m going to end up in jail.”

  The district court sentenced Antelope to an additional ten
months in prison and twenty-six months of supervised release
with the same conditions. Antelope appealed a final time, and
we consider the issues presented by his consolidated fourth
and fifth appeals.

                        DISCUSSION

I.   RIPENESS

   We turn first to the government’s argument that Antelope’s
Fifth Amendment claim is not yet ripe for review. The consti-
tutional component of ripeness is a jurisdictional prerequisite.
Cal. Pro-Life Council, Inc. v. Getman, 328 F.3d 1088, 1093-
94 & n.2 (9th Cir. 2003) (noting that the question of ripeness
often “coincides squarely with standing’s injury in fact
prong”). Whether Antelope’s claim is sufficiently mature to
justify appellate review is a question of law we consider de
novo. Laub v. United States Dep’t of the Interior, 342 F.3d
1080, 1084 (9th Cir. 2003).

   [1] To determine whether Antelope suffered an injury in
fact, we must identify “an invasion of a legally protected
interest which is (a) concrete and particularized; and (b)
actual or imminent, not conjectural or hypothetical.” Id. at
1085. Here, Antelope’s appeal centers around his claimed
right to be free of unconstitutional compulsion: Under his the-
ory, the government violated his Fifth Amendment right when
it conditioned his probation and supervised release on the sub-
mission of a sexual autobiography that we may assume would
                   UNITED STATES v. ANTELOPE                1159
have revealed prosecutable offenses. From Antelope’s per-
spective, in whose shoes we stand when deciding this thresh-
old issue of justiciability, he has already suffered the very
serious and non-hypothetical injury of imprisonment after he
invoked his Fifth Amendment right. In other words, “[i]f his
legal argument is correct, he has already suffered constitu-
tional injury.” United States v. Purvis, 940 F.2d 1276, 1278
(9th Cir. 1991) (holding ripe the defendant’s challenge to his
supervised release condition, which he had been re-
incarcerated for violating). Antelope’s case history reads like
a never-ending loop tape: he asserts his constitutional rights,
the district court advises him that surely his statements will be
confidential but that he must comply with what he views as
a violation of his constitutional rights, he refuses to comply,
his release is revoked, and Antelope ends up incarcerated.
Indeed, it is difficult to imagine a more paradigmatic “injury
in fact” than actual incarceration. We therefore conclude that
Antelope’s Fifth Amendment claim is ripe for review.

II. THE FIFTH AMENDMENT RIGHT AGAINST
SELF-INCRIMINATION

   Having determined the question justiciable, we address
next Antelope’s claim to the Fifth Amendment privilege
against compelled self-incrimination, an issue that has domi-
nated the five appeals Antelope has filed throughout the
course of these proceedings. Antelope contends that the Fifth
Amendment restrains the government from forcing him to
admit prior wrongdoing unless his statements are protected by
use and derivative use immunity in accordance with Kastigar
v. United States, 406 U.S. 441 (1972). Whether there is merit
to Antelope’s argument is a legal matter, which we decide
without deference to the judgment of the district court. See
United States v. Rubio-Topete, 999 F.2d 1334, 1338 (9th Cir.
1993).

  [2] We ground our analysis in well-settled principles, start-
ing with the Constitution. The Fifth Amendment guarantees
1160                  UNITED STATES v. ANTELOPE
that “[n]o person . . . shall be compelled in any criminal case
to be a witness against himself.” U.S. Const. amend. V. This
right remains available to Antelope despite his conviction. See
Minnesota v. Murphy, 465 U.S. 420, 426 (1984) (“A defen-
dant does not lose this protection by reason of his conviction
of a crime . . . .”); cf. McKune v. Lile, 536 U.S. 24, 48-54
(2002) (O’Connor, J., concurring in 4-1-4 decision) (applying
the full-blown Fifth Amendment analysis to a prisoner’s claim
that the prison’s requirement that he participate in a sex
offender treatment program violated his constitutional right).1

   [3] To establish his Fifth Amendment claim, Antelope must
prove two things: (1) that the testimony desired by the gov-
ernment carried the risk of incrimination, see Murphy, 465
U.S. at 435 n.7 (explaining that the state may compel answers
“as long as it . . . eliminates the threat of incrimination”);
Minor v. United States, 396 U.S. 87, 98 (1969) (rejecting a
Fifth Amendment challenge because the risk of incrimination
was “only imaginary and insubstantial . . . rather than . . . real
and appreciable” (internal quotation marks omitted)), and (2)
that the penalty he suffered amounted to compulsion, see Lef-
kowitz v. Cunningham, 431 U.S. 801, 806 (1977) (“[T]he
touchstone of the Fifth Amendment is compulsion . . . .” ); cf.
Lile v. McKune, 224 F.3d 1175, 1179 (10th Cir. 2000) (“The
privilege has two components: incrimination and compul-
   1
     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 McK-
une] 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 con-
currence as the holding of the Court in McKune.”).
                   UNITED STATES v. ANTELOPE                 1161
sion.”), rev’d, 536 U.S. 24 (2002) (holding the state-imposed
repercussions insufficiently coercive to amount to compul-
sion).

  A.   Incrimination

   The Fifth Amendment privilege is only properly invoked in
the face of “a real and appreciable danger of self-
incrimination.” McCoy v. Comm’r, 696 F.2d 1234, 1236 (9th
Cir. 1983) (internal quotation marks omitted). “If the threat is
remote, unlikely, or speculative, the privilege does not apply
. . . .” Id. Thus, the Constitution offers no protection to an
individual who, for example, asserts a general intent to refuse
to answer any questions at a court hearing. See United States
v. Pierce, 561 F.2d 735, 741-42 (9th Cir. 1977) (holding that
the probationer’s Fifth Amendment claim could not be evalu-
ated because he had tendered an unspecific “blanket refusal”
to answer any questions at a district court hearing designed to
probe his financial condition). Nor does its umbrella shelter
statements whose ability to incriminate is “highly unlikely.”
Seattle Times Co. v. United States Dist. Court, 845 F.2d 1513,
1520 (9th Cir. 1988) (Reinhardt, J., concurring); see also
Minor, 396 U.S. at 98 (“[I]maginary and insubstantial hazards
of incrimination . . . [do not] support a Fifth Amendment
claim.” (internal quotation marks omitted)).

   Instead, because the Fifth Amendment’s self-incrimination
clause was designed “to effect [the] practical and beneficent
purpose” of preventing inquisitorial interrogation, Brown v.
Walker, 161 U.S. 591, 596-97 (1896), it may only be invoked
when the threat of future criminal prosecution is reasonably
particular and apparent. Cf. id. at 598 (“[I]f a prosecution for
a crime . . . is barred by the statute of limitations, [a witness]
is compellable to answer.”); Neal v. Shimoda, 131 F.3d 818,
833 (9th Cir. 1997) (holding that a prison treatment program
requiring inmates to admit guilt of the crime for which they
were imprisoned did not violate the Fifth Amendment because
1162              UNITED STATES v. ANTELOPE
double jeopardy and the terms of their plea agreement insured
that “no admission . . . could be used against them”).

   This is not to say, however, that the prosecutorial sword
must actually strike or be poised to strike. To the contrary, an
individual “need not incriminate himself in order to invoke
the privilege,” McCoy, 696 F.2d at 1236, but may simply
refuse to make any statements that place him at risk. Accord
Seattle Times, 845 F.2d at 1520 (Reinhardt, J., concurring)
(“[I]t is appropriate for a defendant to raise a fifth amendment
objection at the time he is required to [make the potentially
incriminating statements.]”). And as a general rule, counter-
vailing government interests, such as criminal rehabilitation,
do not trump this right. Thus, when “questions put to [a] pro-
bationer, however relevant to his probationary status, call for
answers that would incriminate him in a pending or later
criminal prosecution,” he may properly invoke his right to
remain silent. Murphy, 465 U.S. at 435.

   [4] In this case, Antelope’s risk of incrimination was “real
and appreciable.” The SABER program required Antelope to
reveal his full sexual history, including all past sexual crimi-
nal offenses. Any attempt to withhold information about past
offenses would be stymied by the required complete autobiog-
raphy and “full disclosure” polygraph examination. Based on
the nature of this requirement and Antelope’s steadfast refusal
to comply, it seems only fair to infer that his sexual autobiog-
raphy would, in fact, reveal past sex crimes. Such an infer-
ence would be consistent with the belief of Roger Dowty,
Antelope’s SABER counselor, who suspects Antelope of hav-
ing committed prior sex offenses. The treatment condition
placed Antelope at a crossroads—comply and incriminate
himself or invoke his right against self-incrimination and be
sent to prison. We therefore conclude that Antelope’s success-
ful participation in SABER triggered a real danger of self-
incrimination, not simply a remote or speculative threat.
                     UNITED STATES v. ANTELOPE                      1163
   We have no doubt that any admissions of past crimes
would likely make their way into the hands of prosecutors.
Dowty made clear that he would turn over evidence of past
sex crimes to the authorities. As he explained at Antelope’s
probation revocation hearing, Dowty has reported his clients’
crimes in the past and his reports have led to additional con-
victions. The SABER release form, which Antelope signed,
specifically authorizes Dowty to make such reports.2 And,
were Antelope to reveal any crimes involving minors, Mon-
tana law would require Dowty to report to law enforcement.
See Mont. Code Ann. §§ 41-3-201 to -202 (2003) (requiring
counselors who suspect child abuse to report to the authori-
ties).

   In sum, the evidence shows that, setting the privilege aside,
Antelope would have to reveal past sex crimes to the SABER
counselor; the counselor would likely report the incidents to
the authorities, who could then use Antelope’s admissions to
prosecute and convict him of the additional crimes. Viewed
in this light, very little stands between Antelope’s participa-
tion in SABER and future prosecution. When he invoked his
Fifth Amendment right, Antelope’s situation presented a “real
and appreciable danger,” not a “remote, unlikely, or specula-
tive” risk. See McCoy, 696 F.2d at 1236. We conclude that
Antelope has shown a sufficiently real possibility of incrimi-
nation.

  B.    Compulsion

  The second prong of the self-incrimination inquiry asks
whether the government has sought to “impose substantial
penalties because a witness elects to exercise his Fifth
Amendment right not to give incriminating testimony against
himself.” Cunningham, 431 U.S. at 805. We are mindful that
  2
    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.”
1164               UNITED STATES v. ANTELOPE
an individual choosing silence does not get a free pass against
all possible repercussions. See, e.g., Ohio Adult Parole Auth.
v. Woodard, 523 U.S. 272, 286 (1998) (a state clemency
board may draw “adverse inferences” from an inmate’s failure
to testify on his own behalf at a clemency hearing). Only
“some penalties are so great as to ‘compel’ such testimony,
while others do not rise to that level.” McKune, 536 U.S. at
49 (O’Connor, J., concurring). The Supreme Court’s decision
in McKune requires us to conclude that this level has been
breached in Antelope’s case.

   In McKune, a plurality of four justices concluded that the
penalties faced by the inmate in that case, Robert Lile, for
refusing to make disclosures required under Kansas’s Sexual
Abuse Treatment Program (“SATP”) did not amount to com-
pulsion under the Fifth Amendment. Id. at 29. Lile brought a
§ 1983 action against prison officials, alleging that they had
violated his Fifth Amendment privilege against self-
incrimination by reducing his privileges and transferring him
from medium-security housing to maximum-security housing
as a result of his refusal to disclose his sexual history as
required by SATP.

   The plurality rejected Lile’s argument that his case was
controlled by “the so-called penalty cases” like Garrity v.
New Jersey, 385 U.S. 493, 497-98 (1967) (striking down state
statute forcing public employees “either to forfeit their jobs or
to incriminate themselves”), and Spevack v. Klein, 385 U.S.
511, 516 (1967) (“The threat of disbarment and the loss of
professional standing, professional reputation, and of liveli-
hood are powerful forms of compulsion to make a lawyer
relinquish the privilege.”), where lesser penalties involving
the potential loss of economic livelihood were held unconsti-
tutional. The plurality distinguished those cases because they
“involved free citizens” and were “not easily extended to the
prison context.” McKune, 536 U.S. at 40-41. Relying instead
on prisoner-specific cases like Murphy, 465 U.S. at 434-39
(concluding that there was no Fifth Amendment violation
                   UNITED STATES v. ANTELOPE                1165
where petitioner claimed he felt compelled to incriminate
himself because he feared absent truthful statements his pro-
bation would be revoked), and Woodard, 523 U.S. at 286-88
(concluding that there was no compulsion where a death row
inmate had to choose between incriminating himself at a
clemency interview and having adverse inferences drawn
from his silence), where the Court found no Fifth Amendment
violations despite the use of far harsher penalties such as lon-
ger incarceration or execution, the plurality wrote that “lawful
conviction and incarceration necessarily place limitations on
the exercise of a defendant’s privilege against self-
incrimination.” McKune, 536 U.S. at 38.

   In her concurrence, Justice O’Connor explained that penal-
ties 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 “reduc-
tion 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.

   [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 constitu-
tionally impermissible.
1166               UNITED STATES v. ANTELOPE
   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 com-
pel 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 unconsti-
tutional 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:

    I believe the proper theory should recognize that it
    is generally acceptable to impose the risk of punish-
    ment, 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 one-
    self that go beyond the criminal process and appear,
    starkly, as government attempts to compel testimony
    ....

Id. at 53 (internal citation omitted).

   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
                   UNITED STATES v. ANTELOPE                1167
acceptable for the state to impose harsh penalties on defen-
dants 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 incrimi-
nate oneself that go beyond the criminal process and appear,
starkly, as government attempts to compel testimony.” Id.

   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 mis-
conduct to participating counselors, serves an important reha-
bilitative purpose. See, e.g., id. at 33 (plurality opinion) (“An
important component of [sex offender] rehabilitation pro-
grams 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 poten-
tial 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 prosecu-
torial 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 dis-
tinction” 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
1168                   UNITED STATES v. ANTELOPE
protections offered by the privilege against compelled self-
incrimination”).

   [6] Justice O’Connor made clear in her McKune concur-
rence that she would not have found a penalty of “longer
incarceration” such as that here to be constitutionally permis-
sible. 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.3 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.4
  3
     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.
   4
     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 sen-
tencing court for a probation revocation hearing,” arguing that this condi-
tion 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 privi-
lege would have led to revocation,” given that the state would have pro-
vided 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 proba-
tioner “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
                     UNITED STATES v. ANTELOPE                       1169
   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 Cir-
cuit 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 poly-
graph’s effect on Lee could not amount to constitutional com-
pulsion.

   The First Circuit likewise faced a Fifth Amendment chal-
lenge 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 Amend-
ment challenge, acknowledging that “the polygraph require-
ment 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 sub-

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 super-
vised release ended because he would not make potentially self-
incriminating statements as required by SABER.
1170               UNITED STATES v. ANTELOPE
mit 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 Cir-
cuit 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.

   Although the First and Third Circuits found an interpreta-
tive way around the Fifth Amendment issue, the path of con-
stitutional avoidance taken in York and Lee is unavailable
here. Whether Antelope’s supervised release is actually condi-
tioned 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.

   [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
                  UNITED STATES v. ANTELOPE               1171
supervised release violated his Fifth Amendment right against
self-incrimination.

  C.   Antelope’s Entitlement to Kastigar Immunity

    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 disagree-
ment because the issue is intimately bound up with the resolu-
tion 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 state-
ments. See Kastigar, 406 U.S. at 453 (holding use and deriva-
tive 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 Ante-
lope 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.

    As the Supreme Court has explained, adoption of the gov-
ernment’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 privi-
lege 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 noncriminal case, the privi-
lege 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).
1172               UNITED STATES v. ANTELOPE
   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 incriminat-
ing 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 com-
mencement of a ‘criminal case’ to safeguard the core Fifth
Amendment trial right.” Id.

   In the face of the vast weight of precedent to the contrary,
see, e.g., Murphy, 465 U.S. at 429-40 (discussing circum-
stances 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 con-
tends 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.

   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 jus-
tices 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
                   UNITED STATES v. ANTELOPE                   1173
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 constitu-
tional 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 out-
side the Fifth Amendment’s core,” the privilege’s protections
will only be expanded where “the core guarantee, or the judi-
cial 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 privi-
lege . . . to . . . civil liability”). Simply stated, the holding of
Chavez is tightly bound to its § 1983 context.

   [8] Were Antelope to turn the tables and sue the govern-
ment, Chavez would direct our inquiry to the “core constitu-
tional 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 protec-
tion 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.5
  5
  The scope of the immunity should be consistent with the Supreme
Court’s opinion in Kastigar, 406 U.S. at 453 (holding that “immunity
1174                 UNITED STATES v. ANTELOPE
III.   THE PROHIBITION ON “ANY PORNOGRAPHIC MATERIALS”

   [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 sim-
ilar supervised release term. Guagliardo was prohibited from
possessing “ ‘any pornography,’ including legal adult pornog-
raphy.” 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 indistin-
guishable from the one imposed on Guagliardo. Here, instead
of “any pornography,” we have “any pornographic . . . materi-
als.”

   The government contends that “sexually oriented or sexu-
ally 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 Ante-
lope 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 clarifi-
cation. 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.

IV. THE PROHIBITION ON “ACCESS TO ANY ON-LINE
COMPUTER SERVICE”

  Antelope’s final argument challenges as overbroad the
supervised release term prohibiting him from “possess[ing] or

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 alto-
gether, just from the “use and derivative use” of compelled admissions in
trial against him. Id.
                  UNITED STATES v. ANTELOPE                1175
us[ing] a computer with access to any ‘on-line computer ser-
vice’ at any location (including employment) without the
prior written approval of the probation department.”

   [10] As Antelope acknowledges, we recently rejected pre-
cisely 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 fed-
eral 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 defen-
dant” 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.

                       CONCLUSION

  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.
