The Court's unconstitutional conditions cases, such as Velazquez, are not strictly controlling, since they do not require a showing that recipients who comply with the conditions attached to federal funding will, as state actors, violate others' constitutional rights, as is the case under the fourth prong of Dole. However, they are highly instructive. The Supreme Court's pronouncements in the unconstitutional conditions cases on what is necessary for a plaintiff to mount a successful First Amendment facial challenge to an exercise of Congress's spending power have not produced a seamless web. For example, in Rust v. Sullivan, 500 U.S. 173 (1991), the Court rejected a First Amendment facial challenge to federal regulations prohibiting federally funded healthcare clinics from providing counseling concerning the use of abortion as a method of family planning, explaining that: Petitioners are challenging the facial validity of the regulations. Thus, we are concerned only with the question whether, on their face, the regulations are both authorized by the Act and can be construed in such a manner that they can be applied to a set of individuals without infringing upon constitutionally protected rights. Petitioners face a heavy burden in seeking to have the regulations invalidated as facially unconstitutional. . . . The fact that the regulations might operate unconstitutionally under some conceivable set of circumstances is insufficient to render them wholly invalid.
Id. at 183 (internal quotation marks, alterations, and citation omitted). In contrast, NEA v. Finley, 524 U.S. 569 (1998), which also involved a facial First Amendment challenge to an exercise of Congress's spending power, articulated a somewhat more liberal test of facial validity than Rust, explaining that "[t]o prevail, respondents must demonstrate a substantial risk that application of the provision will lead to the suppression of speech." Id. at 580. Against this background, it is unclear to us whether, to succeed in facially invalidating CIPA on the grounds that it will "induce the States to engage in activities that would themselves be unconstitutional," Dole, 483 U.S. at 210, plaintiffs must show that it is impossible for public libraries to comply with CIPA's conditions without violating the First Amendment, or rather simply that CIPA will effectively restrict library patrons' access to substantial amounts of constitutionally protected speech, therefore causing many libraries to violate the First Amendment. However, we need not resolve this issue. Rather, we may assume without deciding, for purposes of this case, that a facial challenge to CIPA requires plaintiffs to show that any public library that complies with CIPA's conditions will necessarily violate the First Amendment and, as explained in detail below, we believe that CIPA's constitutionality fails even under this more restrictive test of facial validity urged on us by the government. Because of the inherent limitations in filtering technology, public libraries can never comply with CIPA without blocking access to a substantial amount of speech that is both constitutionally protected and fails to meet even the filtering companies' own blocking criteria. We turn first to the governing legal principles to be applied to the facts in order to determine whether the First Amendment permits a library to use the filtering technology mandated by CIPA. 3. Level of Scrutiny Applicable to Content-based Restrictions on Internet Access in Public Libraries
In analyzing the constitutionality of a public library's use of Internet filtering software, we must first identify the appropriate level of scrutiny to apply to this restriction on patrons' access to speech. While plaintiffs argue that a public library's use of such filters is subject to strict scrutiny, the government maintains that the applicable standard is rational basis review. If strict scrutiny applies, the government must show that the challenged restriction on speech is narrowly tailored to promote a compelling government interest and that no less restrictive alternative would further that interest. United States v. Playboy Entm't Group, Inc., 529 U.S. 803, 813 (2000). In contrast, under rational basis review, the challenged restriction need only be reasonable; the government interest that the restriction serves need not be compelling; the restriction need not be narrowly tailored to serve that interest; and the restriction "need not be the most reasonable or the only reasonable limitation." Cornelius v. NAACP Legal Def. & Educ. Fund, 473 U.S. 788, 808 (1985).
Software filters, by definition, block access to speech on the basis of its content, and content-based restrictions on speech are generally subject to strict scrutiny. See Playboy, 529 U.S. at 813 ("[A] content-based speech restriction . . . can stand only if it satisfies strict scrutiny."). Strict scrutiny does not necessarily apply to content-based restrictions on speech, however, where the restrictions apply only to speech on government property, such as public libraries. "[I]t is . . . well settled that the government need not permit all forms of speech on property that it owns and controls." Int'l Soc'y for Krishna Consciousness, Inc. v. Lee, 505 U.S. 672, 678 (1992). We perforce turn to a discussion of public forum doctrine. 1. Overview of Public Forum Doctrine The government's power to restrict speech on its own property is not unlimited. Rather, under public forum doctrine, the extent to which the First Amendment permits the government to restrict speech on its own property depends on the character of the forum that the government has created. See Cornelius v. NAACP Legal Def. & Educ. Fund, Inc., 473 U.S. 788 (1985). Thus, the First Amendment affords greater deference to restrictions on speech in those areas considered less amenable to free expression, such as military bases, see Greer v. Spock, 424 U.S. 828 (1976), jail grounds, see Adderley v. Florida, 385 U.S. 39 (1966), or public airport terminals, see Int'l Soc'y for Krishna Consciousness, Inc. v. Lee, 505 U.S. 672 (1992), than to restrictions on speech in state universities, see Rosenberger v. Rector & Visitors of Univ. of Va., 515 U.S. 819 (1995), or streets, sidewalks and public parks, see Frisby v. Schultz, 487 U.S. 474 (1988); Hague v. CIO, 307 U.S. 496 (1939). The Supreme Court has identified three types of fora for purposes of identifying the level of First Amendment scrutiny applicable to content-based restrictions on speech on government property: traditional public fora, designated public fora, and nonpublic fora. Traditional public fora include sidewalks, squares, and public parks: [S]treets and parks . . . have immemorially been held in trust for the use of the public and, time out of mind, have been used for purposes of assembly, communicating thoughts between citizens, and discussing public questions. Such use of the streets and public places has, from ancient times, been a part of the privileges, immunities, rights, and liberties of citizens.
Hague, 307 U.S. at 515. "In these quintessential public forums, . . . [f]or the State to enforce a content-based exclusion it must show that its regulation is necessary to serve a compelling state interest and that it is narrowly drawn to achieve that end." Perry Educ. Ass'n v. Perry Local Educs. Ass'n, 460 U.S. 37, 45 (1983); see also Int'l Soc'y for Krishna Consciousness, 505 U.S. at 678 ("[R]egulation of speech on government property that has traditionally been available for public expression is subject to the highest scrutiny."); Frisby, 487 U.S. at 480 ("[W]e have repeatedly referred to public streets as the archetype of a traditional public forum."). A second category of fora, known as designated (or limited) public fora, "consists of public property which the State has opened for use by the public as a place for expressive activity." Perry, 460 U.S. at 46. Whereas any content-based restriction on the use of traditional public fora is subject to strict scrutiny, the state is generally permitted, as long as it does not discriminate on the basis of viewpoint, to limit a designated public forum to certain speakers or the discussion of certain subjects. See Perry, 460 U.S. at 45 n.7. Once it has defined the limits of a designated public forum, however, "[r]egulation of such property is subject to the same limitations as that governing a traditional public forum." Int'l Soc'y for Krishna Consciousness, 505 U.S. at 678. Examples of designated fora include university meeting facilities, see Widmar v. Vincent, 454 U.S. 263 (1981), school board meetings, see City of Madison Joint School Dist. v. Wisc. Employment Relations Comm'n, 429 U.S. 167 (1976), and municipal theaters, see Southeastern Promotions, Ltd. v. Conrad, 420 U.S. 546 (1975).
The third category, nonpublic fora, consists of all remaining public property. "Limitations on expressive activity conducted on this last category of property must survive only a much more limited review. The challenged regulation need only be reasonable, as long as the regulation is not an effort to suppress the speaker's activity due to disagreement with the speaker's view." Int'l Soc'y for Krishna Consciousness, 505 U.S. at 679. 2. Contours of the Relevant Forum: the Library's Collection as a Whole or the Provision of Internet Access?
To apply public forum doctrine to this case, we must first determine whether the appropriate forum for analysis is the library's collection as a whole, which includes both print and electronic resources, or the library's provision of Internet access. Where a plaintiff seeks limited access, for expressive purposes, to governmentally controlled property, the Supreme Court has held that the relevant forum is defined not by the physical limits of the government property at issue, but rather by the specific access that the plaintiff seeks: Although . . . as an initial matter a speaker must seek access to public property or to private property dedicated to public use to evoke First Amendment concerns, forum analysis is not completed merely by identifying the government property at issue. Rather, in defining the forum we have focused on the access sought by the speaker. When speakers seek general access to public property, the forum encompasses that property. In cases in which limited access is sought, our cases have taken a more tailored approach to ascertaining the perimeters of a forum within the confines of the government property. Cornelius v. NAACP Legal Def. & Educ. Fund, Inc., 473 U.S. 788, 801 (1985).
Thus, in Cornelius, where the plaintiffs were legal defense and political advocacy groups seeking to participate in the Combined Federal Campaign charity drive, the Court held that the relevant forum, for First Amendment purposes, was not the entire federal workplace, but rather the charity drive itself. Id. at 801. Similarly, in Perry Education Association v. Perry Local Educators' Association, 460 U.S. 37 (1983), which addressed a union's right to access a public school's internal mail system and teachers' mailboxes, the Court identified the relevant forum as the school's mail system, not the public school as a whole. In Widmar v. Vincent, 454 U.S. 263 (1981), in which a student group challenged a state university's restrictions on use of its meeting facilities, the Court identified the relevant forum as the meeting facilities to which the plaintiffs sought access, not the state university generally. And in Christ's Bride Ministries, Inc. v. SEPTA, 148 F.3d 242 (3d Cir. 1998), involving a First Amendment challenge to the removal of advertisements from subway and commuter rail stations, the Third Circuit noted that the forum at issue was not the rail and subway stations as a whole, but rather the advertising space within the stations. Id. at 248. Although these cases dealt with the problem of identifying the relevant forum where speakers are claiming a right of access, we believe that the same approach applies to identifying the relevant forum where the parties seeking access are listeners or readers.
In this case, the patron plaintiffs are not asserting a First Amendment right to compel public libraries to acquire certain books or magazines for their print collections. Nor are the Web site plaintiffs claiming a First Amendment right to compel public libraries to carry print materials that they publish. Rather, the right at issue in this case is the specific right of library patrons to access information on the Internet, and the specific right of Web publishers to provide library patrons with information via the Internet. Thus, the relevant forum for analysis is not the library's entire collection, which includes both print and electronic media, such as the Internet, but rather the specific forum created when the library provides its patrons with Internet access. Although a public library's provision of Internet access does not resemble the conventional notion of a forum as a well- defined physical space, the same First Amendment standards apply. See Rosenberger v. Rector & Visitors of Univ. of Va., 515 U.S. 819, 830 (1995) (holding that a state university's student activities fund "is a forum more in a metaphysical than a spatial or geographic sense, but the same principles are applicable"); see also Cornelius, 473 U.S. at 801 (identifying the Combined Federal Campaign charity drive as the relevant unit of analysis for application of public forum doctrine). 3. Content-based Restrictions in Designated Public Fora
Unlike nonpublic fora such as airport terminals, see Int'l Soc'y for Krishna Consciousness, Inc. v. Lee, 505 U.S. 672 (1992), military bases, see Greer v. Spock, 424 U.S. 828 (1976), jail grounds, see Adderley v. Florida, 385 U.S. 39 (1966), the federal workplace, see Cornelius v. NAACP Legal Def. & Educ. Fund, 473 U.S. 788, 805 (1985), and public transit vehicles, see Lehman v. City of Shaker Heights, 418 U.S. 298 (1974), the purpose of a public library in general, and the provision of Internet access within a public library in particular, is "for use by the public . . . for expressive activity," Perry Educ. Ass'n v. Perry Local Educs. Ass'n, 460 U.S. 37, 45 (1983), namely, the dissemination and receipt by the public of a wide range of information. We are satisfied that when the government provides Internet access in a public library, it has created a designated public forum. See Mainstream Loudoun v. Bd. of Trustees of the Loudoun County Library, 24 F. Supp. 2d 552, 563 (E.D. Va. 1998); cf. Kreimer v. Bureau of Police, 958 F.2d 1242, 1259 (3d Cir. 1992) (holding that a public library is a limited public forum). Relying on those cases that have recognized that government has leeway, under the First Amendment, to limit use of a designated public forum to narrowly specified purposes, and that content-based restrictions on speech that are consistent with those purposes are subject only to rational basis review, the government argues for application of rational basis review to public libraries' decisions about which content to make available to their patrons via the Internet. See Rosenberger, 515 U.S. 819, 829 (1995) ("The necessities of confining a forum to the limited and legitimate purposes for which it was created may justify the State in reserving it for certain groups or for the discussion of certain topics."); Perry, 460 U.S. at 46 n.7 (1983) ("A public forum may be created for a limited purpose such as use by certain groups . . . or for the discussion of certain subjects.").