“…the data is then routed – in whole or in part – through the eight AT&T buildings, where the NSA taps into it. By monitoring what it calls the “peering circuits” at the eight sites, the spy agency can collect “not only AT&T’s data, they get all the data that’s interchanged between AT&T’s network and other companies,” according to Mark Klein, a former AT&T technician who worked with the company for 22 years.”
Source: The NSA’s Hidden Spy Hubs in Eight U.S. Cities
