The National Security Agency is collecting some 5 billion records a day on the locations of cellphones around the world, The Washington Post reported on Wednesday, citing documents from US intelligence whistle-blower Edward Snowden.

The information is added to a gigantic database that shows the locations of "at least hundreds of millions of cellphones" worldwide, a stunning revelation that suggests the eavesdropping agency has created a mass surveillance tool, according to the Post report.

The article comes six months after the first bombshell leaks from Snowden, a former information technology subcontractor for the NSA who says he spilled secrets to spark public debate on the agency's widespread surveillance activities.

Snowden faces espionage charges but has fled to Russia, where he has been granted asylum.

Of the NSA surveillance programs revealed to date, including spying on foreign leaders and the collection of Internet "meta-data", the geolocation project appears to represent the agency's largest in scale and scope.

The NSA declined to comment on the report when contacted by AFP.

The data is scooped up by tapping into cables that link domestic and foreign cellphone networks across the globe, the Post said.

The location data is gathered with the help of 10 "sigads", or signals intelligence activity designators.

In an example given by the Post, one sigad called "STORMBREW" collects data from two unnamed corporate firms that administer interception equipment. Then "NSA asks nicely for tasking/updates," according to leaked documents.

Information from the cellphones of US citizens traveling abroad also forms part of the database.

Because cellphones broadcast their locations even when there is no call made or text sent, NSA analysts are able to use mathematical techniques to comb through location data and track patterns of movement over time for a given suspect, it said.

The analytic methods used by the agency to sift through location data are known as CO-TRAVELER, according to the report.

Although the vast majority of cellphone users are of no interest to the spy agency, the NSA gathers the bulk data to try to track known "intelligence targets" and their unknown associates, the paper said.

Even the use of disposable cellphones that users switch on and off to make only brief calls in the hopes of avoiding authorities are noted by the system.

According to the Post, CO-TRAVELER combs for new devices connecting to a cell tower after another cellphone is used for the last time.

The NSA insists it does not intentionally track the location data of Americans, but it ends up receiving details that show the whereabouts of domestic mobile devices "incidentally", wrote the Post, which also quoted intelligence officials.

US officials told the Post that the programs that collect geolocation data are legal and designed only to gather intelligence about foreign militants or other "targets" deemed a threat to the United States.

The volume of information flowing in from the program is "outpacing our ability to ingest, process and store" data, according to a May 2012 internal NSA briefing leaked to the Post.

Agence France-Presse

(China Daily 12/06/2013 page12)