Classified documents provided by whistleblower Edward Snowden show that the National Security Agency indeed worked urgently to target bitcoin users around the world — and wielded at least one mysterious source of information to “help track down senders and receivers of Bitcoins,” according to a top-secret passage in an internal NSA report dating to March 2013.





The data source appears to have leveraged the NSA’s ability to harvest and analyze raw, global internet traffic while also exploiting an unnamed software program that purported to offer anonymity to users, according to other documents.



