Via Dave Farber; Ryan Singel:

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.