The NSA Worked to "Track Down" Bitcoin Users, Snowden Documents Reveal
https://theintercept.com/2018/03/20/the-nsa-worked-to-track-down-bitcoin-users-snowden-documents-reveal/
https://theintercept.com/2018/03/20/the-nsa-worked-to-track-down-bitcoin-users-snowden-documents-reveal/