This case challenges an act of Congress that makes the use of filtering software by public libraries a condition of the receipt of federal funding. The Internet, as is well known, is a vast, interactive medium based on a decentralized network of computers around the world. Its most familiar feature is the World Wide Web (the "Web"), a network of computers known as servers that provide content to users. The Internet provides easy access to anyone who wishes to provide or distribute information to a worldwide audience; it is used by more than 143 million Americans. Indeed, much of the world's knowledge accumulated over centuries is available to Internet users almost instantly. Approximately 10% of the Americans who use the Internet access it at public libraries. And approximately 95% of all public libraries in the United States provide public access to the Internet.
While the beneficial effect of the Internet in expanding the amount of information available to its users is self-evident, its low entry barriers have also led to a perverse result facilitation of the widespread dissemination of hardcore pornography within the easy reach not only of adults who have every right to access it (so long as it is not legally obscene or child pornography), but also of children and adolescents to whom it may be quite harmful. The volume of pornography on the Internet is huge, and the record before us demonstrates that public library patrons of all ages, many from ages 11 to 15, have regularly sought to access it in public library settings. There are more than 100,000 pornographic Web sites that can be accessed for free and without providing any registration information, and tens of thousands of Web sites contain child pornography. Libraries have reacted to this situation by utilizing a number of means designed to insure that patrons avoid illegal (and unwanted) content while also enabling patrons to find the content they desire. Some libraries have trained patrons in how to use the Internet while avoiding illegal content, or have directed their patrons to "preferred" Web sites that librarians have reviewed. Other libraries have utilized such devices as recessing the computer monitors, installing privacy screens, and monitoring implemented by a "tap on the shoulder" of patrons perceived to be offending library policy. Still others, viewing the foregoing approaches as inadequate or uncomfortable (some librarians do not wish to confront patrons), have purchased commercially available software that blocks certain categories of material deemed by the library board as unsuitable for use in their facilities. Indeed, 7% of American public libraries use blocking software for adults. Although such programs are somewhat effective in blocking large quantities of pornography, they are blunt instruments that not only "underblock," i.e., fail to block access to substantial amounts of content that the library boards wish to exclude, but also, central to this litigation, "overblock," i.e., block access to large quantities of material that library boards do not wish to exclude and that is constitutionally protected.
Most of the libraries that use filtering software seek to block sexually explicit speech. While most libraries include in their physical collection copies of volumes such as The Joy of Sex and The Joy of Gay Sex, which contain quite explicit photographs and descriptions, filtering software blocks large quantities of other, comparable information about health and sexuality that adults and teenagers seek on the Web. One teenager testified that the Internet access in a public library was the only venue in which she could obtain information important to her about her own sexuality. Another library patron witness described using the Internet to research breast cancer and reconstructive surgery for his mother who had breast surgery. Even though some filtering programs contain exceptions for health and education, the exceptions do not solve the problem of overblocking constitutionally protected material. Moreover, as we explain below, the filtering software on which the parties presented evidence in this case overblocks not only information relating to health and sexuality that might be mistaken for pornography or erotica, but also vast numbers of Web pages and sites that could not even arguably be construed as harmful or inappropriate for adults or minors.
The Congress, sharing the concerns of many library boards, enacted the Children's Internet Protection Act ("CIPA"), Pub. L. No. 106-554, which makes the use of filters by a public library a condition of its receipt of two kinds of subsidies that are important (or even critical) to the budgets of many public libraries grants under the Library Services and Technology Act, 20 U.S.C. Sec. 9101 et seq. ("LSTA"), and so-called "E-rate discounts" for Internet access and support under the Telecommunications Act, 47 U.S.C. Sec. 254. LSTA grant funds are awarded, inter alia, in order to: (1) assist libraries in accessing information through electronic networks, and (2) provide targeted library and information services to persons having difficulty using a library and to underserved and rural communities, including children from families with incomes below the poverty line. E-rate discounts serve the similar purpose of extending Internet access to schools and libraries in low-income communities. CIPA requires that libraries, in order to receive LSTA funds or E-rate discounts, certify that they are using a "technology protection measure" that prevents patrons from accessing "visual depictions" that are "obscene," "child pornography," or in the case of minors, "harmful to minors." 20 U.S.C. Sec. 9134(f)(1)(A) (LSTA); 47 U.S.C. Sec. 254(h)(6)(B) & (C) (E- rate).
The plaintiffs, a group of libraries, library associations, library patrons, and Web site publishers, brought this suit against the United States and others alleging that CIPA is facially unconstitutional because: (1) it induces public libraries to violate their patrons' First Amendment rights contrary to the requirements of South Dakota v. Dole, 483 U.S. 203 (1987); and (2) it requires libraries to relinquish their First Amendment rights as a condition on the receipt of federal funds and is therefore impermissible under the doctrine of unconstitutional conditions. In arguing that CIPA will induce public libraries to violate the First Amendment, the plaintiffs contend that given the limits of the filtering technology, CIPA's conditions effectively require libraries to impose content-based restrictions on their patrons' access to constitutionally protected speech. According to the plaintiffs, these content- based restrictions are subject to strict scrutiny under public forum doctrine, see Rosenberger v. Rector & Visitors of Univ. of Va., 515 U.S. 819, 837 (1995), and are therefore permissible only if they are narrowly tailored to further a compelling state interest and no less restrictive alternatives would further that interest, see Reno v. ACLU, 521 U.S. 844, 874 (1997). The government responds that CIPA will not induce public libraries to violate the First Amendment, since it is possible for at least some public libraries to constitutionally comply with CIPA's conditions. Even if some libraries' use of filters might violate the First Amendment, the government submits that CIPA can be facially invalidated only if it is impossible for any public library to comply with its conditions without violating the First Amendment.
Pursuant to CIPA, a three-judge Court was convened to try the issues. Pub. L. No. 106-554. Following an intensive period of discovery on an expedited schedule to allow public libraries to know whether they need to certify compliance with CIPA by July 1, 2002, to receive subsidies for the upcoming year, the Court conducted an eight-day trial at which we heard 20 witnesses, and received numerous depositions, stipulations and documents. The principal focus of the trial was on the capacity of currently available filtering software. The plaintiffs adduced substantial evidence not only that filtering programs bar access to a substantial amount of speech on the Internet that is clearly constitutionally protected for adults and minors, but also that these programs are intrinsically unable to block only illegal Internet content while simultaneously allowing access to all protected speech. As our extensive findings of fact reflect, the plaintiffs demonstrated that thousands of Web pages containing protected speech are wrongly blocked by the four leading filtering programs, and these pages represent only a fraction of Web pages wrongly blocked by the programs. The plaintiffs' evidence explained that the problems faced by the manufacturers and vendors of filtering software are legion. The Web is extremely dynamic, with an estimated 1.5 million new pages added every day and the contents of existing Web pages changing very rapidly. The category lists maintained by the blocking programs are considered to be proprietary information, and hence are unavailable to customers or the general public for review, so that public libraries that select categories when implementing filtering software do not really know what they are blocking.
There are many reasons why filtering software suffers from extensive over- and underblocking, which we will explain below in great detail. They center on the limitations on filtering companies' ability to: (1) accurately collect Web pages that potentially fall into a blocked category (e.g., pornography); (2) review and categorize Web pages that they have collected; and (3) engage in regular re-review of Web pages that they have previously reviewed. These failures spring from constraints on the technology of automated classification systems, and the limitations inherent in human review, including error, misjudgment, and scarce resources, which we describe in detail infra at 58-74. One failure of critical importance is that the automated systems that filtering companies use to collect Web pages for classification are able to search only text, not images. This is crippling to filtering companies' ability to collect pages containing "visual depictions" that are obscene, child pornography, or harmful to minors, as CIPA requires. As will appear, we find that it is currently impossible, given the Internet's size, rate of growth, rate of change, and architecture, and given the state of the art of automated classification systems, to develop a filter that neither underblocks nor overblocks a substantial amount of speech.
The government, while acknowledging that the filtering software is imperfect, maintains that it is nonetheless quite effective, and that it successfully blocks the vast majority of the Web pages that meet filtering companies' category definitions (e.g., pornography). The government contends that no more is required. In its view, so long as the filtering software selected by the libraries screens out the bulk of the Web pages proscribed by CIPA, the libraries have made a reasonable choice which suffices, under the applicable legal principles, to pass constitutional muster in the context of a facial challenge. Central to the government's position is the analogy it advances between Internet filtering and the initial decision of a library to determine which materials to purchase for its print collection. Public libraries have finite budgets and must make choices as to whether to purchase, for example, books on gardening or books on golf. Such content-based decisions, even the plaintiffs concede, are subject to rational basis review and not a stricter form of First Amendment scrutiny. In the government's view, the fact that the Internet reverses the acquisition process and requires the libraries to, in effect, purchase the entire Internet, some of which (e.g., hardcore pornography) it does not want, should not mean that it is chargeable with censorship when it filters out offending material. The legal context in which this extensive factual record is set is complex, implicating a number of constitutional doctrines, including the constitutional limitations on Congress's spending clause power, the unconstitutional conditions doctrine, and subsidiary to these issues, the First Amendment doctrines of prior restraint, vagueness, and overbreadth. There are a number of potential entry points into the analysis, but the most logical is the spending clause jurisprudence in which the seminal case is South Dakota v. Dole, 483 U.S. 203 (1987). Dole outlines four categories of constraints on Congress's exercise of its power under the Spending Clause, but the only Dole condition disputed here is the fourth and last, i.e., whether CIPA requires libraries that receive LSTA funds or E-rate discounts to violate the constitutional rights of their patrons. As will appear, the question is not a simple one, and turns on the level of scrutiny applicable to a public library's content-based restrictions on patrons' Internet access. Whether such restrictions are subject to strict scrutiny, as plaintiffs contend, or only rational basis review, as the government contends, depends on public forum doctrine.
The government argues that, in providing Internet access, public libraries do not create a public forum, since public libraries may reserve the right to exclude certain speakers from availing themselves of the forum. Accordingly, the government contends that public libraries' restrictions on patrons' Internet access are subject only to rational basis review. Plaintiffs respond that the government's ability to restrict speech on its own property, as in the case of restrictions on Internet access in public libraries, is not unlimited, and that the more widely the state facilitates the dissemination of private speech in a given forum, the more vulnerable the state's decision is to restrict access to speech in that forum. We agree with the plaintiffs that public libraries' content-based restrictions on their patrons' Internet access are subject to strict scrutiny. In providing even filtered Internet access, public libraries create a public forum open to any speaker around the world to communicate with library patrons via the Internet on a virtually unlimited number of topics. Where the state provides access to a "vast democratic forum[]," Reno v. ACLU, 521 U.S. 844, 868 (1997), open to any member of the public to speak on subjects "as diverse as human thought," id. at 870 (internal quotation marks and citation omitted), the state's decision selectively to exclude from the forum speech whose content the state disfavors is subject to strict scrutiny, as such exclusions risk distorting the marketplace of ideas that the state has facilitated. Application of strict scrutiny finds further support in the extent to which public libraries' provision of Internet access uniquely promotes First Amendment values in a manner analogous to traditional public fora such as streets, sidewalks, and parks, in which content-based restrictions are always subject to strict scrutiny.
Under strict scrutiny, a public library's use of filtering software is permissible only if it is narrowly tailored to further a compelling government interest and no less restrictive alternative would serve that interest. We acknowledge that use of filtering software furthers public libraries' legitimate interests in preventing patrons from accessing visual depictions of obscenity, child pornography, or in the case of minors, material harmful to minors. Moreover, use of filters also helps prevent patrons from being unwillingly exposed to patently offensive, sexually explicit content on the Internet.