In 1997, more than 75 percent of all public libraries in the United States offered free Internet access to their patrons, with more going on-line every day.The Internet seems to be a perfect match for libraries; both provide information for their users on practically any subject. But the Internet’s wide range of topics and opinions is putting public libraries in the middle of a free speech debate.

The public library is the sole source of Internet access for many Americans. Most parents do not want their children exposed to pornography and other offensive material that is easily accessible over the Internet. For this reason, some libraries have installed programs on their computers that filter or block objectionable material on-line. This action has raised charges of censorship by some librarians and commentators who believe that libraries should be committed to...