An anonymous reader writes: Newly disclosed NSA documents show that the agency gained access to billions of emails through a "highly collaborative" relationship with AT&T. The company provided access from 2003 to 2013, including technical assistance to carry out court orders permitting wiretapping. "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 new files don't indicate whether the partnership currently exists, but the government has been doing its best to keep corporate partnerships hidden. The article also notes that "In 2011, AT&T began handing over 1.1 billion domestic cellphone calling records a day to the N.S.A. after 'a push to get this flow operational prior to the 10th anniversary of 9/11,' according to an internal agency newsletter."