The government pays AT&T to place its employees in drug-fighting units around the country. Those employees sit alongside Drug Enforcement Administration agents and local detectives and supply them with the phone data from as far back as 1987.

via Drug Agents Use Vast Phone Trove, Eclipsing N.S.A.’s – NYTimes.com.

The program was started in 2007, according to the slides, and has been carried out in great secrecy.

There once was a time, back when the old AT&T existed,  when all  phone companies viewed customer privacy sacrosanct.