The National Security Agency is reportedly gathering nearly five billion records a day on the whereabouts of cell phones globally.
The move enabled the agency to track the movements of individuals and map their relationships in ways that would have been previously unimaginable.
According to the Washington Post, the records contain a vast database that stores information about the locations of at least hundreds of millions of devices, the officials and documents revealed, which were provided by former NSA contractor Edward Snowden.
The NSA does not target Americans' location data by design, but it acquires a substantial amount of information on the whereabouts of domestic cellphones.
U.S. officials said the programs that collect and analyze location data are lawful and intended strictly to develop intelligence about foreign targets, the report added.
