The ruling throws out the closely watched case of Kathleen R. v. City of Livermore, in which a mother has been seeking damages over pornographic material obtained by her 12-year-old son on library computers. A three-justice panel dismissed the suit this week, citing a federal law that grants immunity to any Internet service provider for information obtained over their services.
"A public library is in a 'damned if you do, damned if you don't' situation in deciding whether to restrict access to the Internet from its computers to prevent harm to minors," the court wrote. The opinion pointed out that a previous case in Virginia found libraries that impose Internet filters may be sued under the First Amendment.
The decision comes as regulators consider how to implement a new federal law that requires public schools and libraries to use technology to filter out Web images deemed inappropriate for children or risk losing federal funds.
The measure, known as the Children's Internet Protection Act (CHIPA), is backed by conservative groups who have been fighting for years to protect children from the Web's seamier side.
Civil liberties groups oppose the new law, with the American Civil Liberties Union (ACLU) and American Library Association planning to file suits saying it violates the First Amendment by blocking access to content.
Livermore doesn't receive any of the federal funds that trigger the filtering requirement, so it wouldn't be forced to filter even if CHIPA stands.