NSA officials declined to identify which phone and e-mail databases are used to create the social network diagrams, and the documents provided by Snowden do not specify them.
The agency did say that the large database of Americans’ domestic phone call records, which was revealed by Snowden in June and caused bipartisan alarm in Washington, was excluded. (NSA officials have previously acknowledged that the agency has done limited analysis in that database, collected under provisions of the US Patriot Act, exclusively for people who might be linked to terrorism suspects.)
However, the agency has multiple collection programs and databases, the former officials said, adding that the social networking analyses relied on both domestic and international metadata. They spoke only on the condition of anonymity because the information was classified.
The concerns in the US since Snowden’s revelations have largely focused on the scope of the agency’s collection of the private data of Americans and the potential for abuse.
The new documents provide a rare window into what the NSA actually does with the information it gathers.
A series of agency PowerPoint presentations and memos describe how the NSA has been able to develop software and other tools — one document cited a new generation of programs that “revolutionize” data collection and analysis — to unlock as many secrets about individuals as possible.
The agency, led by US General Keith Alexander, an unabashed advocate for more weapons in the hunt for information about the nation’s adversaries, clearly views its collections of metadata as one of its most powerful resources.
NSA analysts can exploit that information to develop a portrait of an individual, one that is perhaps more complete and predictive of behavior than could be obtained by listening to phone conversations or reading e-mails, experts say.
Phone and e-mail logs, for example, allow analysts to identify people’s friends and associates, detect where they were at a certain time, acquire clues to religious or political affiliations, and pick up sensitive information like regular calls to a psychiatrist’s office, messages to an extramarital partner or exchanges with a fellow plotter.
“Metadata can be very revealing,” said Orin Kerr, a law professor at George Washington University. “Knowing things like the number someone just dialed or the location of the person’s cellphone is going to allow them to assemble a picture of what someone is up to.”
The NSA had been pushing for more than a decade to obtain the rule change allowing the analysis of Americans’ phone and e-mail data.
Intelligence officials had been frustrated that they had to stop when a contact chain hit a telephone number or e-mail address believed to be used by an American, even though it might yield valuable intelligence primarily concerning a foreigner who was overseas, according to documents previously disclosed by Snowden.
NSA officials also wanted to employ the agency’s advanced computer analysis tools to sift through its huge databases with much greater efficiency.