The scale and longevity of the data storage appears to be
unmatched by other government programs, including the N.S.A.’s
gathering of phone call logs under the Patriot Act. The N.S.A.
stores the data for nearly all calls in the United States,
including phone numbers and time and duration of calls, for
Hemisphere covers every call that passes through an AT&T switch —
not just those made by AT&T customers — and includes calls dating
back 26 years, according to Hemisphere training slides bearing the
logo of the White House Office of National Drug Control Policy.
Some four billion call records are added to the database every
day, the slides say; technical specialists say a single call may
generate more than one record. Unlike the N.S.A. data, the
Hemisphere data includes information on the locations of callers.
The program was started in 2007, according to the slides, and has
been carried out in great secrecy. “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.