AT&T’s cooperation has involved a broad range of classified activities, according to the documents, which date from 2003 to 2013. AT&T has given the NSA access, through several methods covered under different legal rules, to billions of emails as they have flowed across its domestic networks. It provided technical assistance in carrying out a secret court order permitting the wiretapping of all Internet communications at the United Nations headquarters, a customer of AT&T.
The NSA’s top-secret budget in 2013 for the AT&T partnership was more than twice that of the next-largest such program, according to the documents. The company installed surveillance equipment in at least 17 of its Internet hubs on American soil, far more than its similarly sized competitor, Verizon. And its engineers were the first to try out new surveillance technologies invented by the eavesdropping agency.
One document reminds NSA officials to be polite when visiting AT&T facilities, noting: “This is a partnership, not a contractual relationship.”
The documents, provided by the former agency contractor Edward Snowden, were jointly reviewed by The New York Times and ProPublica.