GoKawiilAT&T's Room 641A exposed as NSA internet surveillance hub in San Francisco
A secret room inside AT&T's Folsom Street facility in San Francisco, known internally as the SG3 Secure Room, was found to contain a Narus STA 6400 device capable of intercepting and analyzing high-speed internet traffic. The setup used beam splitters attached to fiber optic backbone lines, giving it access to both domestic and international communications passing through the building. Former AT&T technician Mark Klein exposed the facility, prompting a 2006 lawsuit from the Electronic Frontier Foundation.