AT&T provided National Security Agency eavesdroppers with full access to its customers' phone calls, and shunted its customers' internet traffic to data-mining equipment installed in a secret room in its San Francisco switching center, according to a former AT&T worker cooperating in the Electronic Frontier Foundation's lawsuit against the company.
Mark Klein, a retired AT&T communications technician, submitted an affidavit in support of the EFF's lawsuit this week. That class action lawsuit, filed in federal court in San Francisco last January, alleges that AT&T violated federal and state laws by surreptitiously allowing the government to monitor phone and internet communications of AT&T customers without warrants.
On Wednesday, the EFF asked the court to issue an injunction prohibiting AT&T from continuing the alleged wiretapping, and filed a number of documents under seal, including three AT&T documents that purportedly explain how the wiretapping system works.
According to a statement released by Klein's attorney, an NSA agent showed up at the San Francisco switching center in 2002 to interview a management-level technician for a special job. In January 2003, Klein observed a new room being built adjacent to the room housing AT&T's #4ESS switching equipment, which is responsible for routing long distance and international calls.
"I learned that the person whom the NSA interviewed for the secret job was the person working to install equipment in this room," Klein wrote. "The regular technician work force was not allowed in the room."