NSA uses metadata ‘to create sophisticated graphs’ of US citizens’ social connections

The US National Security Agency has been exploiting US citizens’ personal information drawn from its large collection of metadata to create complex graphs of social connections for foreign intelligence purposes, the latest Snowden leaks have revealed.

Documents obtained by the New York Times from the former NSA contractor Edward Snowden say that the practice has been going on since November 2010, after restrictions prohibiting the agency from working with  US citizens’ data were “lifted” by NSA officials.

The NSA was then authorized to conduct “large-scale graph analysis on very large sets of communications metadata without having to check foreignness” of the e-mail addresses, phone numbers or any other identifiers, the documents reportedly said.

The policy shift was intended to help the agency “discover and track” connections between intelligence targets overseas and people in the US, a January 2011 NSA memorandum cited in the documents explained.

According to the report, the agency has been allowed to “enrich” their communications data with materials obtained from public, commercial and other sources while preparing the graphs. Such sources reportedly include Facebook profiles, bank codes, insurance information, passenger manifests, voter registration rolls and GPS location information, as well as property records and unspecified tax data.