Gal Vallerius was a darknet narcotics dealer in France who went by the alias “OxyMonster.” U.S. government agents were able to track Bitcoin transactions to and from “OxyMonster” and noticed that Bitcoin usually went to Vallerius’s account on LocalBitcoins.com, a site for trading Bitcoin over-the-counter. Jay Weaver for the Miami Herold reported:
In August, agents learned that “OxyMonster” was using a certain bitcoin address for the sales transactions. They soon analyzed incoming and outgoing transactions from that bitcoin address and discovered that most of them went to Vallerius on Localbitcoins.com
U.S. agents arrested him when he traveled to the U.S. for a beard growing competition.