Two civil rights groups on Wednesday claimed a shared victory in getting the FBI to withdraw a national security letter (NSL) issued to the Internet Archive secretly seeking information on a patron of the online library.

The withdrawal of the letter and an associated gag order followed a legal challenge from the American Civil Liberties Union (ACLU) and the Electronic Frontier Foundation (EFF). In a press conference earlier Wednesday, the two groups and the Internet Archive said they had reached a settlement agreement with the FBI, under which the latter has withdrawn its NSL and agreed to the unsealing of the case, after a four-month negotiation.

"The shroud of secrecy from gag provisions has distorted the public debate," over NSLs, said Ann Brick, a staff attorney with ACLU's northern California chapter. "It's only because the gag has been lifted that the Archive can serve as an example" to others served with similar letters, she said.

The FBI uses National Security Letters to get information on personal customer records from Internet Service Providers, banks and other financial institutions and organizations. Unlike formal subpoenas, no formal judicial review is required to serve an NSL. According to an FAQ on the FBI's Web site, NSLs can only be used to seek certain transactional information, such as subscriber information, billing records and ISP's log-in information. NSL's cannot be used to acquire the actual content of any communications. The letters have been used widely by the FBI, the CIA and the Department of Defense as a counter-terrorism tool after the September 11 attacks.

The letter that's the subject of the settlement announced today was served by the FBI (download PDF) on the Internet Archive, a non-profit Internet library, last November. The letter basically asked the library to provide the FBI with the name, address, "electronic communication transaction records," transaction and activity logs, and all email header information associated with a patron of the online library.

The FBI letter noted that the information was being sought in connection with a counter-terrorism investigation. It instructed Internet Archive not to disclose the letter to anyone except to legal counsel and to those to whom disclosure was necessary in order to comply with the letter. In addition, the NSL instructed Internet Archives not to take any action that could potentially alert the individual in question of the investigation.

"It was depressing as hell," to receive the letter said Brewster Kahle, founder of Internet Archives. "What made it particularly difficult for us was that I couldn't discuss it with anybody. This whole thing [became] a big mess because of the gag order," Kahle said.

The letter was formally handled by the EFF, which acts as legal counsel to the Internet Archive. In a response to the FBI letter in December 2007 the Archive voluntarily provided some information but also challenged the security letter on the grounds that it was unconstitutional, said Kurt Opsahl, senior staff attorney at the EFF.