In Case You Thought We Were Joking: Room 641A

Room 641A, Folsom St. AT&T Facility, San Francisco, CA

Whistleblower saw AT&T assist Bush administration.

To find out for yourself (from WIRED's Threat Level):

If you're a Windows user, fire up an MS-DOS command prompt. Now type tracert followed by the domain name of the website, e-mail host, VoIP switch, or whatever destination you're interested in. Watch as the program spits out your route, line by line.

In the above example, my traffic is jumping from Level 3 Communications to AT&T's network in San Francisco, presumably over the OC-48 circuit that AT&T tapped on February 20th, 2003, according to the Klein docs. The magic string you're looking for is sffca.ip.att.net. If it's present immediately above or below a non-att.net entry, then -- by Klein's allegations -- your packets are being copied into room 641A, and from there, illegally, to the NSA. Of course, if Marcus is correct and AT&T has installed these secret rooms all around the country, then any att.net entry in your route is a bad sign.