The National Security Agency is tracking hundreds of millions of cellphones worldwide and storing nearly 5 billion records every day on users' whereabouts and their contacts, The Washington Post reported Wednesday.
Citing unnamed U.S. officials and top-secret documents provided by former NSA contractor Edward Snowden, the Post writes that the agency has the ability "to track the movements of individuals - and map their relationships - in ways that would have been previously unimaginable."
The NSA said it does not intentionally target Americans' whereabouts but gets location data "incidentally," which the agency has declared lawful and aimed at foreign intelligence targets.
The agency is tapping the cables that connect mobile networks in the United States and overseas, while also gathering information from the cellphones of tens of millions of Americans traveling abroad each year, according to an NSA official who had permission to speak to the Post.
"New projects created to analyze that data have provided the intelligence community with what amounts to a mass surveillance tool," the paper writes.
In scale, scope and potential impact on privacy, the efforts to collect and analyze location data may be unsurpassed among the NSA surveillance programs that have been disclosed since June. Analysts can find cellphones anywhere in the world, retrace their movements and expose hidden relationships among individuals using them.
The NSA "has no reason to suspect that the movements of the overwhelming majority of cellphone users would be relevant to national security," the Post writes.
"There is no element of the intelligence community that under any authority is intentionally collecting bulk cellphone location information about cellphones in the United States," said Robert Litt, general counsel for the Office of the Director of National Intelligence, which oversees the NSA.