The US Federal Bureau of Investigation has withdrawn a secret demand that the Internet Archive, an online library, provide the agency with a user's personal information after the Web site challenged the records request in court.

The FBI sent a national security letter, or NSL, to the Internet Archive in November and included a gag order barring site founder Brewster Kahle from talking to anyone other than his lawyers about the request. Kahle, the Electronic Frontier Foundation (EFF) and the American Civil Liberties Union (ACLU) filed a lawsuit to challenge the subpoena, arguing that the NSL program is unconstitutional, and the FBI withdrew the NSL on April 22.

The settlement between the FBI and the Internet Archive allowed Kahle to break the gag order, a standard part of an NSL request. The Internet Archive's challenge of the NSL is only the third case that the ACLU is aware of in which an NSL has been challenged in court, said Melissa Goodman an attorney for the civil liberties group's National Security Project.

"The NSLs basically allow the FBI to demand extremely sensitive personal information about innocent people without any prior court approval, often in total secrecy," Goodman said Wednesday.

The NSL program, expanded when Congress passed the antiterrorism Patriot Act shortly after the Sept. 11, 2001, attacks on the US, allows the FBI and other US government agencies to issue administrative subpoenas to US businesses for customer and other personal information.

FBI Assistant Director John Miller issued a statement about the case Wednesday. "The information requested in the national security letter was relevant to an ongoing, authorized national security investigation," he said. "National security letters remain indispensable tools for national security investigations and permit the FBI to gather the basic building blocks for our counterterrorism and counterintelligence investigations."

Although the settlement keeps parts of the FBI request secret, Kahle applauded the lawsuit and settlement, saying it will show other businesses how to challenge NSLs. The FBI issued nearly 200,000 NSLs between 2003 and 2006, according to a US Department of Justice inspector general's report.

"We see this as an unqualified success," Kahle said during a news conference. "The goal here was to help other recipients of NSLs ... understand that you can push back on these."