Wired has an informative, deeply terrifying, interview with Mark Klein the whistleblower who outed AT&T for spying for the NSA.
WN: How many people worked in or on that room?
Klein: Two people worked in the secret room, and they were management technicians. The first was downsized out of his job at the end of 2003, and was replaced by a second. A third management tech did not work in the secret room but knew what was going on. I knew all three of them. These guys would occasionally stop by the water cooler to chat with the union technicians in their office area on Folsom Street and they said things they probably shouldn’t have.
And did things they probably should have. —MEGHANN MARCO
Spying in the Death Star: The AT&T Whistle-Blower Tells His Story [Wired]