Bitcoin Fog was an anonymization service: for a fee, it mixed a bunch of people’s bitcoins up so that it was hard to figure out where any individual coins came from.
It goes on to show the blockchain evidence that identifies Sterlingov’s purchase of that Liberty Reserve currency with bitcoins: He first exchanged euros for the bitcoins on the early cryptocurrency exchange Mt.
Gox accounts that used Sterlingov’s home address and phone number, and even a Google account that included a Russian-language document on its Google Drive offering instructions for how to obscure Bitcoin payments.