The AT&T internal database contains records of every call that went through an AT&T switch, user info, and location information. It was originally constructed to facilitate billing, and contains records of all calls going through AT&T switches since 1987. Training slides for Hemisphere personnel (sent to the Times by an activist) stress the secrecy of the project -
“All requestors are instructed to never refer to Hemisphere in any official document,” one slide says. A search of the Nexis database found no reference to the program in news reports or Congressional hearings.The Obama administration has acknowledged the existence of the Hemisphere Project and its extraordinary scale and scope, but suggested that it's not a privacy issue because the database is maintained by AT&T, and not the government.
AT&T declined comment.Jameel Jaffer, deputy legal director of the American Civil Liberties Union, said the 27-slide PowerPoint presentation, evidently updated this year to train AT&T employees for the program, “certainly raises profound privacy concerns.”“I’d speculate that one reason for the secrecy of the program is that it would be very hard to justify it to the public or the courts,” he said.
Source - Drug Agents Use Vast Phone Trove, Eclipsing N.S.A.'s, New York Times