http://e55lzoju6enqswtvm66sk3uqukcin3377ehgiorplj4d7qyssipls4yd.onion/en/blog/what-is-a-bitcoin-mixer.php
The same thing happened when authorities managed to discover a link between Bitcoin money transfer and Fancy Bear, a large Russian cyber espionage group that was suspected to be responsible for a handful of large-scale hacking and illegal activities that support the interests of the Russian government.