Documents [PDF] obtained by the Electronic Frontier Foundation show that the FBI asked telecommunications companies to turn over information about people in contact with individuals the FBI was investigating, though a degree removed from any suspicious activity and presumably innocent. As Eric Lichtblau reported in the New York Times this morning:

The F.B.I. cast a much wider net in its terrorism investigations than it has previously acknowledged by relying on telecommunications companies to analyze phone-call patterns of the associates of Americans who had come under suspicion, according to newly obtained bureau records.

The documents indicate that the Federal Bureau of Investigation used secret demands for records to obtain data not only on individuals it saw as targets but also details on their "community of interest" ? the network of people that the target was in contact with. The bureau stopped the practice early this year in part because of broader questions raised about its aggressive use of the records demands, which are known as national security letters, officials said.

The letters are part of the second set of FBI documents released in response to a Freedom of Information Act (FOIA) lawsuit seeking information about the FBI's misuse of National Security Letters (NSLs). In June, a federal judge ordered [PDF] the Bureau to disclose additional information responsive to EFF's request every month. We anticipate that this material will continue to reveal details about the Bureau's use ? and abuse ? of NSL authority. For more information about EFF's FOIA work, visit our FOIA Litigation for Accountable Government (FLAG) Project page.

Update, 9/11: We've added more analysis in a follow-up post here.