WASHINGTON -- Librarians, writers and booksellers are challenging a controversial provision of the USA Patriot Act that they consider a violation of privacy with the potential to widen the digital divide for low-income and rural Americans who depend on library computers.

Carla Hayden, president of the American Library Association, says her organization is worried about the "chilling effect" of Section 215, which gave law enforcement officials easier access to book sale and library records and prohibits librarians from telling patrons or even supervisors when records are being reviewed.

The Bush administration and other supporters of the anti-terrorist measure say the provision dealing with book sales and library records has seldom, if ever, been used and that adequate oversight is provided to prevent abuses.

The library association nevertheless has joined with the American Bookseller's Association and the PEN American Center, a writer's organization, to launch a campaign aimed at gathering 1 million signatures calling for repeal of Section 215. Petitions will be placed in bookstores, libraries and on the Web site www.readerprivacy.org.

While ALA officials are concerned about Section 215's potential "chilling effect" on all library users, it might pose particular problems for people who have no other access to computers, said Hayden, who is speaking today at an invitation-only event at the University of Pittsburgh's School of Information Sciences.

"For many people, we are the main on-ramp to the information superhighway," Hayden said in a telephone interview.

Although libraries always have cooperated with law enforcement investigations, Section 215 lowers the legal standard for obtaining library records and allows "fishing expeditions," Hayden contended.

Some libraries have put up signs warning patrons that their borrowing records and library computer usage may be secretly inspected by law enforcement officials. But many libraries now use computerized systems that wipe clean a patron's borrowing record as soon as a book is returned.

Mark Corallo, a Justice Department spokesman, says Section 215 is "very limited," but important in ensuring that libraries aren't seen as "terrorist safety zones." Requests to obtain library records -- or medical, business and other types of records -- under Section 215 must be approved by a federal judge who is part of a secret court operating under the Foreign Intelligence Surveillance Act.

Last September, Corallo noted, Attorney General John Ashcroft declassified information relating to the number of times that Section 215 had been used to obtain records to that point. At that time, "the number was zero," he said.

To Hayden and a bipartisan group of senators and representatives, however, that just proves the provision isn't needed. At least four states and 270 communities have called for changes to Section 215, and there are several proposals currently pending in Congress to limit or repeal it.

The issue has been spotlighted in the presidential campaign. President Bush wants to extend Patriot Act provisions, including Section 215, when they expire next year. "The terrorist threat will not expire on that schedule," Bush said in his State of the Union speech.

Sen. John Kerry, D-Mass., the presumptive Democratic nominee, voted for the Patriot Act when it passed shortly after the Sept. 11, 2001, terrorist attacks. But Kerry now says the Bush administration has misused the law and that he would change it to "eliminate the potential of fishing expeditions into people's library and business records."

Groups that support changes to Section 215 span the nation's political spectrum, including the American Civil Liberties Union and the American Conservative Union. A group in Pittsburgh -- the "Pittsburgh Bill of Rights Defense Campaign" -- is urging the city and the state to join other communities in calling for the repeal of Section 215.

Lane Cigna, a spokeswoman for the Carnegie Library of Pittsburgh, said the library system "is in compliance with the USA Patriot Act." But Cigna noted that library officials are particularly concerned about Section 215's "gag order," which places a veil of secrecy over law enforcement requests for library records.