opinion: THORNBURGH, ATTORNEY GENERAL OF THE UNITED STATES, et al. v. ABBOTT et al.
  No. 87-1344.
  Argued November 8, 1988
  Decided May 15, 1989
  Blackmun, J., delivered the opinion of the Court, in which Rehnquist, C. J., and White, O’Connor, Scalia, and Kennedy, JJ., joined. Stevens, J., filed an opinion concurring in part and dissenting in part, in which Brennan and Marshall, JJ., joined, post, p. 420.
  Deputy Solicitor General Bryson argued the cause for petitioners. With him on the briefs were Solicitor General Fried, Acting Assistant Attorney General Dennis, Robert H. Klonoff, and Andrew Levchuk.
  Steven Ney argued the cause for respondents. With him on the brief were Edward I. Koren, Alvin J. Bronstein, and Steven R. Shapiro.
  Briefs of amici curiae urging reversal were filed for the State of Florida et al. by Robert A. Buttenvorth, Attorney General of Florida, and Jason Vail, Assistant Attorney General, and Robert R. Gates, Deputy Attorney General of Idaho; and for the State of Missouri et al. by William L. Webster, Attorney General of Missouri, and Kelly Mescher, Assistant Attorney General, Steve Clark, Attorney General of Arkansas, James T. Jones, Attorney General of Idaho, and W. J. Michael Cody, Attorney General of Tennessee.
  Briefs of amici curiae urging affirmance were filed for the Association of American Publishers, Inc., et al. by R. Bruce Rich; and for the Correctional Association of New York by John Boston and William J. Rold.
  Justice Blackmun
  delivered the opinion of the Court.
  I
  Regulations promulgated by the Federal Bureau of Prisons broadly permit federal prisoners to receive publications from the “outside,” but authorize prison officials to reject incoming-publications found to be detrimental to institutional security. For 15 years, respondents, a class of inmates and certain publishers, have claimed that these regulations violate their First Amendment rights under the standard of review enunciated in Procunier v. Martinez, 416 U. S. 396 (1974). They mount a facial challenge to the regulations as well as a challenge to the regulations as applied to 46 specific publications excluded by the Bureau.
  After a 10-day bench trial, the District Court refrained from adopting the Martinez standard. Instead, it favored an approach more deferential to the judgment of prison authorities and upheld the regulations without addressing the propriety of the 46 specific exclusions. App. to Pet. for Cert. 26a, 43a-47a. The Court of Appeals, on the other hand, utilized the Martinez standard, found the regulations wanting, and remanded the case to the District Court for an individualized determination of the constitutionality of the 46 exclusions. Abbott v. Meese, 263 U. S. App. D. C. 186, 824 F. 2d 1166 (1987).
  Petitioners, officials of the Department of Justice and the Bureau of Prisons, sought certiorari. We granted the writ in order to determine the appropriate standard of review. Meese v. Abbott, 485 U. S. 1020 (1988).
  We now hold that the District Court correctly anticipated that the proper inquiry in this case is whether the regulations are “reasonably related to legitimate penological interests,” Turner v. Safley, 482 U. S. 78, 89 (1987), and we conclude that under this standard the regulations are facially valid. We therefore disagree with the Court of Appeals on the issue of facial validity, but we agree with that court’s remand of the case to the District Court for a determination of the validity of the regulations as applied to each of the 46 publications.
  II
  We are concerned primarily with the regulations set forth at 28 CFR §§540.70 and 540.71 (1988), first promulgated in 1979. These generally permit an inmate to subscribe to, or to receive, a publication without prior approval, but authorize the warden to reject a publication in certain circumstances. The warden may reject it “only if it is determined detrimental to the security, good order, or discipline of the institution or if it might facilitate criminal activity.” § 540.71(b). The warden, however, may not reject a publication “solely because its content is religious, philosophical, political, social or sexual, or because its content is unpopular or repugnant.” Ibid. The regulations contain a nonexhaustive list of criteria which may support rejection of a publication. The warden is prohibited from establishing an excluded list of publications: each issue of a subscription publication is to be reviewed separately. § 540.71(c). The regulatory criteria for rejecting publications have been supplemented by Program Statement No. 5266.5, which provides further guidance on the subject of sexually explicit material.
  The regulations provide procedural safeguards for both the recipient and the sender. The warden may designate staff to screen and, where appropriate, to approve incoming publications, but only the warden may reject a publication. § 540.70(b). The warden must advise the inmate promptly in writing of the reasons for the rejection, §540.71(d), and must provide the publisher or sender with a copy of the rejection letter, § 540.71(e). The notice must refer to “the specific article(s) or material(s) considered objectionable.” § 540.71(d). The publisher or sender may obtain an independent review of the warden’s rejection decision by a timely writing to the Regional Director of the Bureau. § 540.71(e). An inmate may appeal through the Bureau’s Administrative Remedy Procedure. See §§542.10 to 542.16. The warden is instructed to permit the inmate to review the rejected material for the purpose of filing an appeal “unless such review may provide the inmate with information of a nature which is deemed to pose a threat or detriment to the security, good order or discipline of the institution or to encourage or instruct in criminal activity.” §540.71(d).
  III
  There is little doubt that the kind of censorship just described would raise grave First Amendment concerns outside the prison context. It is equally certain that “[p]rison walls do not form a barrier separating prison inmates from the protections of the Constitution,” Turner v. Safley, 482 U. S., at 84, nor do they bar free citizens from exercising their own constitutional rights by reaching out to those on the “inside,” id., at 94-99; Bell v. Wolfish, 441 U. S. 520 (1979); Jones v. North Carolina Prisoners’ Labor Union, Inc., 433 U. S. 119 (1977); Pell v. Procunier, 417 U. S. 817 (1974). We have recognized, however, that these rights must be exercised with due regard for the “inordinately difficult undertaking” that is modern prison administration. Turner v. Safley, 482 U. S., at 85.
  In particular, we have been sensitive to the delicate balance that prison administrators must strike between the order and security of the internal prison environment and the legitimate demands of those on the “outside” who seek to enter that environment, in person or through the written word. Many categories of noninmates seek access to prisons. Access is essential to lawyers and legal assistants representing prisoner clients, see Procunier v. Martinez, 416 U. S. 396 (1974), to journalists seeking information about prison conditions, see Pell v. Procunier, supra, and to families and friends of prisoners who seek to sustain relationships with them, see Procunier v. Martinez, supra. All these claims to prison access undoubtedly are legitimate; yet prison officials may well conclude that certain proposed interactions, though seemingly innocuous to laymen, have potentially significant implications for the order and security of the prison. Acknowledging the expertise of these officials and that the judiciary is “ill equipped” to deal with the difficult and delicate problems of prison management, this Court has afforded considerable deference to the determinations of prison administrators who, in the interest of security, regulate the relations between prisoners and the outside world. Id., at 404-405.
  In this case, there is no question that publishers who wish to communicate with those who, through subscription, willingly seek their point of view have a legitimate First Amendment interest in access to prisoners. The question here, as it has been in our previous First Amendment cases in this area, is what standard of review this Court should apply to prison regulations limiting that access.
  Martinez was our first significant decision regarding First Amendment rights in the prison context. There, the Court struck down California regulations concerning personal correspondence between inmates and noninmates, regulations that provided for censorship of letters that “unduly complain,” “magnify grievances,” or “expres[s] inflammatory political, racial, religious or other views or beliefs.” Id., at 399. We reviewed these regulations under the following standard:
  “First, the regulation or practice in question must further an important or substantial governmental interest unrelated to the suppression of expression. Prison officials . . . must show that a regulation authorizing mail censorship furthers one or more of the substantial governmental interests of security, order, and rehabilitation. Second, the limitation of First Amendment freedoms must be no greater than is necessary or essential to the protection of the particular governmental interest involved. Thus a restriction on inmate correspondence that furthers an important or substantial interest of penal administration will nevertheless be invalid if its sweep is unnecessarily broad.” Id., at 413-414.
  It is clear from this language, however, that we did not deprive prison officials of the degree of discretion necessary to vindicate “the particular governmental interest involved.” Accordingly, we said:
  “Some latitude in anticipating the probable consequences of allowing certain speech in a prison environment is essential to the proper discharge of an administrator’s duty. But any regulation or practice that restricts inmate correspondence must be generally necessary to protect one or more . . . legitimate governmental interests.” Id., at 414.
  The Court’s subsequent decisions regarding First Amendment rights in the prison context, however, laid down a different standard of review from that articulated in Martinez. As recently explained in Turner, these later decisions, which we characterized as involving “prisoners’ rights,” adopted a standard of review that focuses on the reasonableness of prison regulations: the relevant inquiry is whether the actions of prison officials were “reasonably related to legitimate penological interests.” 482 U. S., at 89. The Court ruled that “such a standard is necessary if ‘prison administrators . . . , and not the courts, [are] to make- the difficult judgments concerning institutional operations.’” Ibid., quoting Jones v. North Carolina Prisoners’ Labor Union, Inc., 433 U. S., at 128. The Court set forth in Turner the development of this reasonableness standard in the respective decisions in Pell and Jones and in Block v. Rutherford, 468 U. S. 576 (1984), and we need not repeat that discussion here.
  The Court’s decision to apply a reasonableness standard in these cases rather than Martinez’ less deferential approach stemmed from its concern that language in Martinez might be too readily understood as establishing a standard of “strict” or “heightened” scrutiny, and that such a strict standard simply was not appropriate for consideration of regulations that are centrally concerned with the maintenance of order and security within prisons. See Turner v. Safley, 482 U. S., at 81, 87, 89. Specifically, the Court declined to apply the Martinez standard in “prisoners’ rights” cases because, as was noted in Turner, Martinez could be (and had been) read to require a strict “least restrictive alternative” analysis, without sufficient sensitivity to the need for discretion in meeting legitimate prison needs. 482 U. S., at 89-90. The Court expressed concern that “every administrative judgment would be subject to the possibility that some court somewhere would conclude that it had a less restrictive way of solving the problem at hand,” id., at 89, and rejected the costs of a “least restrictive alternative” rule as too high. Id., at 90. See also O’Lone v. Estate of Shabazz, 482 U. S. 342, 350 (1987) (refusing to apply a least restrictive alternative standard for regulation of prisoner work rules having an impact on religious observance).
  We do not believe that Martinez should, or need, be read as subjecting the decisions of prison officials to a strict “least restrictive means” test. As noted, Martinez required no more than that a challenged regulation be “generally necessary” to a legitimate governmental interest. 416 U. S., at 414. Certainly, Martinez required a close fit between the challenged regulation and the interest it purported to serve. But a careful reading of Martinez suggests that our rejection of the regulation at issue resulted not from a least restrictive means requirement, but from our recognition that the regulated activity centrally at issue in that case — outgoing personal correspondence from prisoners — did not, by its very nature, pose a serious threat to prison order and security." We pointed out in Martinez that outgoing correspondence that magnifies grievances or contains inflammatory racial views cannot reasonably be expected to present a danger to the community inside the prison. Id., at 416. In addition, the implications for security are far more predictable. Dangerous outgoing correspondence is more likely to fall within readily identifiable categories: examples noted in Martinez include escape plans, plans relating to ongoing criminal activity, and threats of blackmail or extortion. Id., at 412-413. Although we were careful in Martinez not to limit unduly the discretion of prison officials to reject even outgoing letters, we concluded that the regulations at issue were broader than “generally necessary” to protect the interests at stake. Id., at 414.
  In light of these considerations, it is understandable that the Court in Martinez concluded that the regulations there at issue swept too broadly. Where, as in Martinez, the nature of the asserted governmental interest is such as to require a lesser degree of case-by-case discretion, a closer fit between the regulation and the purpose it serves may safely be required. Categorically different considerations — considerations far more typical of the problems of prison administration — apply to the case presently before this Court.
  We deal here with incoming publications, material requested by an individual inmate but targeted to a general audience. Once in the prison, material of this kind reasonably may be expected to circulate among prisoners, with the concomitant potential for coordinated disruptive conduct. Furthermore, prisoners may observe particular material in the possession of a fellow prisoner, draw inferences about their fellow’s beliefs, sexual orientation, or gang affiliations from that material, and cause disorder by acting accordingly. See App. 22-23, 52, 59, 88; see generally Prisoners and the Law 3-14 (I. Robbins ed. 1988) (noting that possession of homosexually explicit material may identify the possessor as homosexual and target him for assault). As the Deputy Solicitor General noted at oral argument: “The prob-' lem is not ... in the individual reading the materials in most cases. The problem is in the material getting into the prison.” Tr. of Oral Arg. 10. See also id., at 26; App. 10. In the volatile prison environment, it is essential that prison officials be given broad discretion to prevent such disorder.
  In Turner, we dealt with incoming personal correspondence from prisoners; the impact of the correspondence on the internal environment of the prison was of great concern. There, we recognized that Martinez was too readily understood as failing to afford prison officials sufficient discretion to protect prison security. In light of these same concerns, we now hold that regulations affecting the sending of a “publication” (see the regulations’ specific definition of this word, n. 4, supra) to a prisoner must be analyzed under the Turner reasonableness standard. Such regulations are “valid if [they are] reasonably related to legitimate penological interests.” Turner, 482 U. S., at 89.
  Furthermore, we acknowledge today that the logic of our analyses in Martinez and Turner requires that Martinez be limited to regulations concerning outgoing correspondence. As we have observed, outgoing correspondence was the central focus of our opinion in Martinez. The implications of outgoing correspondence for prison security are of a categorically lesser magnitude than the implications of incoming materials. Any attempt to justify a similar categorical distinction between incoming correspondence from prisoners (to which we applied a reasonableness standard in Turner) and incoming correspondence from nonprisoners would likely prove futile, and we do not invite it. To the extent that Martinez itself suggests such a distinction, we today overrule that case; the Court accomplished much of this step when it decided Turner.
  In so doing, we recognize that it might have been possible to apply a reasonableness standard to all incoming materials without overruling Martinez: we instead could have made clear that Martinez does not uniformly require the application of a “least restrictive alternative” analysis. We choose not to go that route, however, for we prefer the express flexibility of the Turner reasonableness standard. We adopt the Turner standard in this case with confidence that, as petitioners here have asserted, “a reasonableness standard is not toothless.” Pet. for Cert. 17, n. 10.
  IV
  The Court in Turner identified several factors that are relevant to, and that serve to channel, the reasonableness inquiry.
  The first Turner factor is multifold: we must determine whether the governmental objective underlying the regulations at issue is legitimate and neutral, and that the regulations are rationally related to that objective. We agree with the District Court that this requirement has been met.
  The legitimacy of the Government’s purpose in promulgating these regulations is beyond question. The regulations are expressly aimed at protecting prison security, a purpose this Court has said is “central to all other corrections goals.” Pell v. Procunier, 417 U. S., at 823.
  As to neutrality, “[w]e have found it important to inquire whether prison regulations restricting inmates’ First Amendment rights operated in a neutral fashion, without regard to the content of the expression.” Turner, 482 U. S., at 90. The ban on all correspondence between certain classes of inmates at issue in Turner clearly met this “neutrality” criterion, as did the restrictions at issue in Pell and Wolfish. The issue, however, in this case is closer.
  On their face, the regulations distinguish between rejection of a publication “solely because its content is religious, philosophical, political, social or sexual, or because its content is unpopular or repugnant” (prohibited) and rejection because the publication is detrimental to security (permitted). 28 CFR §540.71(b)(1988). Both determinations turn, to some extent, on content. But the Court’s reference to “neutrality” in Turner was intended to go no further than its requirement in Martinez that “the regulation or practice in question must further an important or substantial governmental interest unrelated to the suppression of expression.” 416 U. S., at 413. Where, as here, prison administrators draw distinctions between publications solely on the basis of their potential implications for prison security, the regulations are “neutral” in the technical sense in which we meant and used that term in Turner.
  We also conclude that the broad discretion accorded prison wardens by the regulations here at issue is rationally related to security interests. We reach this conclusion for two reasons. The first has to do with the kind of security risk presented by incoming publications. This has been explored above in Part III. The District Court properly found that publications can present a security threat, and that a more closely tailored standard “could result in admission of publications which, even if they did not lead directly to violence, would exacerbate tensions and lead indirectly to disorder.” App. to Pet. for Cert. 32a. Where the regulations at issue concern the entry of materials into the prison, we agree with the District Court that a regulation which gives prison authorities broad discretion is appropriate.
  Second, we are comforted by the individualized nature of the determinations required by the regulation. Under the regulations, no publication may be excluded unless the warden himself makes the determination that it is “detrimental to the security, good order, or discipline of the institution or . . . might facilitate criminal activity.” 28 CFR §§ 540.70(b), 540.71(b) (1988). This is the controlling standard. A publication which fits within one of the “criteria” for exclusion may be rejected, but only if it is determined to meet that standard under the conditions prevailing at the institution at the time. Indeed, the regulations expressly reject certain shortcuts that would lead to needless exclusions. See § 540.70(b) (nondelegability of power to reject publications); § 540.71(c) (prohibition against establishing an excluded list of publications). We agree that it is rational for the Bureau to exclude materials that, although not necessarily “likely” to lead to violence, are determined by the warden to create an intolerable risk of disorder under the conditions of a particular prison at a particular time.
  A second factor the Court in Turner held to be “relevant in determining the reasonableness of a prison restriction ... is whether there are alternative means of exercising the right that remain open to prison inmates.” 482 U. S., at 90. As has already been made clear in Turner and O’Lone, “the right” in question must be viewed sensibly and expansively. The Court in Turner did not require that prisoners be afforded other means of communicating with inmates at other institutions, 482 U. S., at 92, nor did it in O’Lone require that there be alternative means of attending the Jumu’ah religious ceremony, 482 U. S., at 351. Rather, it held in Turner that it was sufficient if other means of expression (not necessarily other means of communicating with inmates in other prisons) remained available, and in O’Lone if prisoners were permitted to participate in other Muslim religious ceremonies. As the regulations at issue in the present case permit a broad range of publications to be sent, received, and read, this factor is clearly satisfied.
  The third factor to be addressed under the Turner analysis is the impact that accommodation of the asserted constitutional right will have on others (guards and inmates) in the prison. 482 U. S., at 90. Here, the class of publications to be excluded is limited to those found potentially detrimental to order and security; the likelihood that such material will circulate within the prison raises the prospect of precisely the kind of “ripple effect” with which the Court in Turner was concerned. Where, as here, the right in question “can be exercised only at the cost of significantly less liberty and safety for everyone else, guards and other prisoners alike,” id., at 92, the courts should defer to the “informed discretion of corrections officials,” id., at 90.
  Finally, Turner held: “[T]he existence of obvious, easy alternatives may be evidence that the regulation is not reasonable, but is an ‘exaggerated response’ to prison concerns. . . . But if an inmate claimant can point to an alternative that fully accommodates the prisoner’s rights at de minimis cost to valid penological interests, a court may consider that as evidence that the regulation does not satisfy the reasonable relationship standard.” 482 U. S., at 90-91. We agree with the District Court that these regulations, on their face, are not an “exaggerated response” to the problem at hand: no obvious, easy alternative has been established.
  Regarding the all-or-nothing rule, we analyze respondents’ proposed alternatives to that rule as alternative means of accommodating respondents’ asserted rights. The District Court discussed the evidence and found, on the basis of testimony in the record, that petitioners’ fear that tearing out the rejected portions and admitting the rest of the publication would create more discontent than the current practice was “reasonably founded.” App. to Pet. for Cert. 34a. The Court of Appeals did not contest the District Court’s factual finding as such, but ruled that upholding a practice merely because it is based upon “reasonably founded” fears is improper under Martinez: the Court of Appeals held that this finding “conflicts with the holding of Martinez that prison administrators have the burden of showing that a restrictive practice is ‘generally necessary.’” 263 U. S. App. D. C., at 194, 824 F. 2d, at 1174.
  As we here do not apply the Martinez standard, we reject the Court of Appeals’ sole ground for questioning the District Court’s findings in this respect. In our view, when prison officials are able to demonstrate that they have rejected a less restrictive alternative because of reasonably founded fears that it will lead to greater harm, they succeed in demonstrating that the alternative they in fact selected was not an “exaggerated response” under Turner. Furthermore, the administrative inconvenience of this proposed alternative is also a factor to be considered and adds additional support to the District Court’s conclusion that petitioners were not obligated to adopt it. See Wolfish, 441 U. S., at 549.
  V
  In sum, we hold that Turner's reasonableness standard is to be applied to the regulations at issue in this case, and that those regulations are facially valid under that standard. We agree with the remand for an examination of the validity of the regulations as applied to any of the 46 publications introduced at trial as to which there remains a live controversy. See 263 U. S. App. D. C., at 196, 824 F. 2d, at 1176.
  The judgment of the Court of Appeals is vacated, and the case is remanded for further proceedings consistent with this opinion.
  It is so ordered.
  As explained in the text, rejection of a publication is authorized “only if it is determined detrimental to the security, good order, or discipline of the institution or if it might facilitate criminal activity.” 28 CFR 8 540.71(b) (1988). References in the text to “prison security” are intended, for the sake of convenience, to refer more broadly to this range of concerns.
  This lawsuit was filed by prisoners in May 1973 and was certified the following year as a class action. In 1978, three publishers, The Prisoners’ Union, Weekly Guardian Associates, and The Revolutionary Socialist League, were added as party plaintiffs. The suit also challenged several prison practices, largely concerning inmate correspondence, that are not at issue here. Individual claims for damages were severed in 1979. A bench trial on the claims for injunctive relief took place in 1981, and a memorandum opinion and accompanying order were issued by the District Court in September 1984. The Court of Appeals predicated its jurisdiction on 28 U. S. C. 8 1292(a)(1) on the ground that the order of the District Court denied respondents injunctive relief. Abbott v. Mee.sr, 263 U. S. App. D. C. 186, 187-188, 824 F. 2d 1166, 1167-1168 (1987).
  When the complaint was filed in 1973, the Bureau had not yet issued regulations dealing with management of federal inmates. See 43 Fed. Reg. 30574 (1978) (proposed rulemaking); 44 Fed. Reg. 38254 (1979) (final rules). References herein to regulations are to those presently in effect. They are identical to the version considered by the District Court and the Court of Appeals. The current version differs in some respects from the 1979 version, but those differences are not material to our present inquiry.
  The term “publication” is defined as “a book (for example, novel, instructional manual), or a single issue of a magazine or newspaper, plus such other materials addressed to a specific inmate as advertising brochures, flyers, and catalogues.” 28 CFR § 540.70(a) (1988).
  Section 540.71(b) reads:
  . . Publications which may be rejected by a Warden include but are not limited to publications which meet one of the following criteria:
  “(1) It depicts or describes procedures for the construction or use of weapons, ammunition, bombs or incendiary devices;
  “(2) It depicts, encourages, or describes methods of escape from correctional facilities, or contains blueprints, drawings or similar descriptions of Bureau of Prisons institutions;
  “(3) It depicts or describes procedures for the brewing of alcoholic beverages, or the manufacture of drugs;
  “(4) It is written in code;
  “(5) It depicts, describes or encourages activities which may lead to the use of physical violence or group disruption;
  “(6) It encourages or instructs in the commission of criminal activity;
  “(7) It is sexually explicit material which by its nature or content poses a threat to the security, good order, or discipline of the institution, or facilitates criminal activity.”
  The Program Statement was promulgated on January 2, 1985, in response to a lawsuit brought by the National Gay Task Force. See App. to Pet. for Cert. 30a (opinion of District Court). By ¶ (a) of the statement, a warden may reject the following types of sexually explicit material pursuant to 28 CFR § 540.71(b)(7) (see n. 5, supra):
  “(1) Homosexual (of the same sex as the institution population).
  “(2) Sado-masochistic.
  “(3) Bestiality.
  “(4) Involving children.”
  Material in categories (1), (2), and (3) may be admitted if the warden determines it “not to pose a threat at the local institution.” ¶ (b)(1). Explicit heterosexual material ordinarily will be admitted. "I (b)(2). Other explicit material may be admitted if it has scholarly, or general social or literary, value. 1 (b)(5). Homosexual material that is not sexually explicit is to be admitted; this includes a publication covering the activities of gay-rights groups or gay religious groups, *: (b)(3), and literary publications with homosexual themes or references, "(b)(4). See 263 U. S. App. D. C., at 197, 824 F. 2d, at 1177.
  Under the Administrative Remedy Procedure, a prisoner who has been unable informally to resolve his difficulty may file a formal written complaint. 28 CFR § 542.13(b) (1988). If the inmate believes he would be adversely affected if the complaint became known at the prison, he may file the complaint with the Regional Director of the Bureau. § 542.13(c). The warden or Regional Director is to respond within 15 or 30 days, respectively. § 542.14. An adverse decision by the Regional Director may be appealed to the General Counsel of the Bureau; an adverse decision by the warden may be appealed to the Regional Director. § 542.15.
  Although the regulations do not so provide, it is the practice of the Bureau to withhold in its entirety any publication containing excludable material. This practice, referred to by the parties as the “all-or-nothing rule," is also at issue in this case.
  We do not think it sufficient to focus, as respondents urge, on the identity of the individuals whose rights allegedly have been infringed. Although the Court took special note in Procunier v. Martinez, 416 U. S. 396 (1974), of the fact that the rights of nonprisoners were at issue, and stated a rule in Turner v. Safley, 482 U. S. 78 (1987), for circumstances in which “a prison regulation impinges on inmates’ constitutional rights,” id,., at 89 (emphasis added), any attempt to forge separate standards for cases implicating the rights of outsiders is out of step with the intervening decisions in Pell v. Procunier, 417 U. S. 817 (1974); Jones v. North Carolina Prisoners’Labor Union, Inc., 433 U. S. 119 (1977); and Bell v. Wolfish, 441 U. S. 520 (1979). These three cases, on which the Court expressly relied in Turner when it announced the reasonableness standard for “inmates’ constitutional rights” cases, all involved regulations that affected rights of prisoners and outsiders.
  Pell involved the right of representatives of the news media to conduct interviews in the prisons in order to inform the public about prison conditions. The asserted right at issue in Jones was the right of a prisoners’ union to send its literature into the prison. In Wolfish, publishers sought to send hardback books into the prison. In all these eases, regulations worked a “consequential restriction on the . . . rights of those who are not prisoners.” Martinez, 416 U. S., at 409. But the Court in Turner observed: “In none of these . . . cases did the Court apply a standard of heightened scrutiny, but instead inquired whether a prison regulation that burdens fundamental rights is ‘reasonably related’ to legitimate penological objectives, or whether it represents an ‘exaggerated response’ to those concerns.” 482 U. S., at 87.
  Martinez has been characterized in subsequent decisions of this Court as a case concerning “written communication by inmates” to noninmate recipients. See Pell, 417 U. S., at 826. See also Houchins v. KQED, Inc., 438 U. S. 1, 12 (1978) (plurality opinion) (distinguishing Martinez as dealing with outsiders' right to receive communications from inside the prison, as opposed to outsiders' right to prison access); id., at 31 (dissenting opinion) (noting Martinez as a case concerning “excessive censorship of outgoing inmate correspondence” (emphasis added)). Indeed, the parties in Martinez stressed that the regulation as enforced dealt “with thoughts expressed in prisoner mail to relatives or friends — mainly outgoing lettern, not matters circulated within the walls." (Emphasis added.) Brief for Appellees in Procunier v. Martinez, O. T. 1973, No. 72-1465, p. 29. Bee also id., at 31; Tr. of Oral Arg. in Martinez, pp. 17, 25 (“[T]he issues in this -case involve what the prisoners are writing outside of the prison”), 31.
  To be sure, some of the regulations at issue in Martinez applied to incoming, as well as outgoing, correspondence. In striking down these regulations as facially overbroad, the Court did not limit its holding to restrictions on outgoing correspondence. But the Court noted that the regulation banning transmission of “inflammatory political, racial, religious or other views” was not “limited to incoming letters.” 416 U. S., at 416. This observation suggests that the Court’s approach to the regulation might have been different had the regulation been so limited.
  The District Court in the present case stated its standard of review: “the Bureau [must] articulate a relationship between its regulations (and practices) and legitimate penological objectives such as internal security. Once the Bureau meets that requirement, the plaintiffs must show by ‘substantial evidence’ that the defendants have ‘exaggerated their response’ to the problems the regulations address.” App. to Pet. for Cert. 46a-47a (citing, among other cases, St. Claire v. Cuyler, 634 F. 2d 109, 114 (CA3 1980)). The District Court did not have the benefit of this Court’s decision in Turner, and the standard of review it applied is not precisely identical to the Turner standard. In particular, it is by no means certain what the District Court meant by “substantial evidence.” We do not pass on any question of evidentiary burdens or burden shifting here, but we conclude that the standard applied by the District Court is sufficiently close to the Turner standard for present purposes to permit reliance on the District Court’s findings.
  Indeed, the Court upheld content distinctions in Jones, where internal distribution of a prisoners’ union’s materials was prohibited while distribution of materials from the Jay cees and Alcoholics Anonymous was permitted. 433 U. S., at 131, n. 8. It upheld these distinctions against an equal protection challenge because the distinctions had a rational basis in the legitimate penological interests of the prisons: in contrast with the prisoners’ union, the Jaycees and Alcoholics Anonymous “were seen as serving a rehabilitative purpose, working in harmony with the goals and desires of the prison administrators, and both had been determined not to pose any threat to the order or security of the institution.” Id., at 134.
  In contrast, the censorship at issue in Martinez closely resembled the kind of censorship which is expressly prohibited by the regulations presently at issue. In Martinez, the regulations barred writings that “unduly complain” or “magnify grievances,” express “inflammatory political, racial, religious or other views,” or are “defamatory” or “otherwise inappropriate.” 416 U. S, at 415. We found in Martinez that “[t]hese regulations fairly invited prison officials and employees to apply their own personal prejudices and opinions as standards for prisoner mail censorship,” and that the purpose of the regulations had not been found “unrelated to the suppression of expression.” Ibid. The regulations at issue in Martinez, therefore, were decidedly not “neutral” in the relevant sense.
  The exercise of discretion called for by these regulations may produce seeming “inconsistencies,” but what may appear to be inconsistent results are not necessarily signs of arbitrariness or irrationality. Given the likely variability within and between institutions over time, see App. to Pet. for Cert. 32a; App. 20-21, 50, greater consistency might be attainable only at the cost of a more broadly restrictive rule against admission of incoming publications. Cf. F. Dostoyevsky, The House of the Dead 40 (Penguin 1985) (prisoners permitted to read only the Bible). Any attempt to achieve greater consistency by broader exclusions might itself run afoul of the second Turner factor, i. e., the presence or absence of “alternative means of exercising the right” in question. 482 U. S., at 90. The regulations at issue here, in our view, strike an acceptable balance.
  Respondents have argued that the record does not support the conclusion that exclusions are in fact based on particular events or conditions at a particular prison; they contend that variability in enforcement of the regulations stems solely from the censors’ subjective views. Brief for Respondents 43-44, n. 37. These contentions go to the adequacy of the regulations as applied, and will be considered on remand.
choices: First Amendment, miscellaneous (cf. comity: First Amendment) commercial speech, excluding attorneys libel, defamation: defamation of public officials and public and private persons libel, privacy: true and false light invasions of privacy legislative investigations: concerning internal security only federal or state internal security legislation: Smith, Internal Security, and related federal statutes loyalty oath or non-Communist affidavit (other than bar applicants, government employees, political party, or teacher) loyalty oath: bar applicants (cf. admission to bar, state or federal or U.S. Supreme Court) loyalty oath: government employees loyalty oath: political party loyalty oath: teachers security risks: denial of benefits or dismissal of employees for reasons other than failure to meet loyalty oath requirements conscientious objectors (cf. military draftee or military active duty) to military service campaign spending (cf. governmental corruption): protest demonstrations (other than as pertains to sit-in demonstrations): demonstrations and other forms of protest based on First Amendment guarantees free exercise of religion establishment of religion (other than as pertains to parochiaid:) parochiaid: government aid to religious schools, or religious requirements in public schools obscenity, state (cf. comity: privacy): including the regulation of sexually explicit material under the 21st Amendment obscenity, federal