Telecom giant AT&T is asking a civil liberties group to return documents that allegedly show the company provided detailed records on millions of Americans to the National Security Agency. In February, the Electronic Frontier Foundation filed a lawsuit alleging AT&T assisted the NSA in eavesdropping on the phone calls and Internet usage of U.S. citizens without court warrants. A former AT&T technician named Mark Klein leaked the internal company documents that describe how AT&T had a secret room in its San Francisco hub which the NSA used to monitor e-mail messages, Internet phone calls, and other Internet traffic. Klein concluded that the equipment permitted “vacuum-cleaner surveillance” of Internet traffic.