The US National Security Agency was interested in the development of the first popular bitcoin critically after some time after its appearance. As it follows from the documents, the NSA developed in 2013 a toolkit that allows tracking the transfers of bitcoins, analyzing the global Internet traffic.
Interest in the NSA was caused by other crypto-currencies, however, bitcoin was given the highest priority, writes The Intercept. At the disposal of the government, perhaps, were data on the activity of users and their computers (for example, the MAC addresses of components and some other information), as well as passwords.
In view of other NSA information collection systems, it is most likely that it is not difficult to identify the owners of bitcoins.
The NSA declined to comment on this information.