05/29/2020

Inside the NSA’s Secret Tool for Mapping Your Social Network

Say "thank you" to “precomputed contact chaining”

In the summer of 2013, I spent my days sifting through the most extensive archive of top-secret files that had ever reached the hands of an American journalist. In a spectacular act of transgression against the National Security Agency (NSA), where he worked as a contractor, Edward Snowden transmitted tens of thousands of classified documents to me, the columnist Glenn Greenwald and documentary filmmaker Laura Poitras.

One of those documents, the first to be made public in June 2013, revealed that the NSA was tracking billions of telephone calls made by Americans inside the U.S. The program became notorious, but its full story has not been told.

The first accounts revealed only bare bones. If you placed a call, whether local or international, the NSA stored the number you dialed, as well as the date, time and duration of the call. It was domestic surveillance, plain and simple. When the story broke, the NSA discounted the intrusion on privacy. The agency collected “only metadata,” it said, not the content of telephone calls. Only on rare occasions, it said, did it search the records for links among terrorists.

Please select this link to read the complete article from WIRED.