Room 641A

Room 641A, in AT&T’s former SBC Communications building at 611 Folsom Street, San Francisco, operated from 2003 as an NSA-run telecommunications interception site with equipment such as a Narus STA 6400 that tapped fiber-optic backbone traffic. In 2006 former AT&T technician Mark Klein revealed its existence, leading to the EFF’s class-action suit Hepting v. AT&T, which was dismissed after Congress granted retroactive immunity to cooperating telecoms. The facility and comparable “black rooms” were later highlighted in PBS Frontline and Nova documentaries.