Russian-Swedish national Roman Sterlingov was convicted by a federal jury in Washington, D.C., for operating Bitcoin Fog between 2011 and 2021.

Bitcoin Fog was one of the longest-running cryptocurrency "tumblers" on the dark web, which cybercriminals from multiple darknet marketplaces used to launder their criminal proceeds.

Mixing services allow users to obfuscate the origin of their digital possessions so that they can be safely withdrawn in "fresh" wallets not associated with illicit activities, making it harder for law enforcement to trace the funds.

Users submit their coins to these platforms and receive an anonymous token that determines the cash-out amounts minus a service fee.

The service takes coins from multiple users and mixes them in a hidden pool before redistributing them, making tracing and linking to the original source difficult.

Being one of the longest-running mixers in the darknet, Bitcoin Fog gained popularity and enjoyed significant traffic.

According to the U.S. Department of Justice (DoJ) announcement, Bitcoin Fog laundered approximately $400 million, a large portion of which is believed to be associated with various crimes.

"Over the course of its decade-long operation, Bitcoin Fog moved over 1.2 million bitcoin, which was valued at approximately $400 million at the time of the transactions," reads the U.S. DoJ announcement.

"The bulk of this cryptocurrency came from darknet marketplaces and was tied to illegal narcotics, computer crimes, identity theft, and child sexual abuse material."

Deputy Attorney General Lisa Monaco highlighted that a dedicated team meticulously traced the Bitcoin transactions through the blockchain to identify and hold Sterlingov accountable.

Sterlingov faces a maximum penalty of 20 years in prison for money laundering conspiracy and sting money laundering charges, along with up to five years for operating an unlicensed money-transmitting business and for money transmission without a license in the District of Columbia.

Mixing services are always in the crosshairs of law enforcement, as they play a vital role in the money laundering process for cybercriminals.

Recent actions by international law enforcement targeted Tornado Cash, ChipMixer, and Blender.io, for aiding ransomware gangs and North Korean hackers in laundering the proceeds of big crypto heists.