If you're a dark web drug dealer, it's probably best to take certain precautions if you want to avoid being caught. Traveling to the US from your home in France to compete in the World Beard and Mustache Championships, for example, seems like an unnecessary risk, but that's how one suspected drug kingpin was caught.

38-year-old French national Gal Vallerius stands accused of acting as an administrator, senior moderator, and vendor for dark web marketplace Dream Market, where visitors can purchase anything from heroin to stolen financial data.

Upon arriving at Atlanta international airport on August 31, Vallerius was arrested and his laptop searched. US Drug Enforcement Administration agents allegedly discovered $500,000 of Bitcoin and Bitcoin cash on the computer, as well a Tor installation and a PGP encryption key for someone called OxyMonster.

Dream Market had been the subject of a multi-agency investigation since February 2016. In addition to his role with the site, agents had identified OxyMonster as a major seller of Oxycontin and crystal meth.

"OxyMonster's vendor profile featured listings for Schedule II controlled substances Oxycontin and Ritalin," testified DEA agent Austin Love. "His profile listed 60 prior sales and five-star reviews from buyers. In addition, his profile stated that he ships from France to anywhere in Europe."

Investigators discovered OxyMonster's real identity by tracing outgoing Bitcoin transactions from his tip jar to wallets registered to Vallerius. Agents then checked his Twitter and Instagram accounts, where they found many writing similarities, including regular use of quotation marks, double exclamation marks, and the word "cheers," as well as intermittent French posts.

The evidence led to a warrant being issued for Vallerius' arrest. When he made his first visit to America to compete in the "full beard 30.1 - 45cm" category at the Austin, Texas event, Vallerius was arrested in Atlanta before he could catch the connecting flight. He is expected to be transferred to Miami, where he faces up to a life sentence for conspiracy to distribute controlled substances.