The Children's Internet Protection Act contains filtering provisions for public libraries that condition the receipt of federal assistance for Internet access and related services on libraries' operation of technological measures that block all patrons' access to obscene and pornographic materials and also block minor patrons' access to material that is "harmful to minors." Now the Supreme Court has agreed to review a trial court's decision that enjoined the government from enforcing these filtering provisions on the basis that they are facially invalid under the First Amendment.
Susanna Frederick Fischer, Does the Children’s Internet Protection Act Induce Public Libraries to Violate the First Amendment?, 2002-2003 PREVIEW U.S. SUP. CT. CAS. 309 (2003).