Buying a gun on the dark web is theoretically pretty easy, but a recent series of busts shows how risky it can be. A six-month joint investigation between law enforcement in Australia and the United States, which involved law enforcement operating undercover as a weapons dealer, has led to a series of arrests and charges spanning continents.

It started when the US Homeland Security Investigations (HSI) identified a 33-year-old US-based dark web vendor back in September 2014, who was selling weapons to a "worldwide client base", according to a press release from the Australian Federal Police (AFP). This arrest was the result of the Australian Customs and Border Protection Service (ACBPS) providing "relevant information" to the HSI (no detail on what this information was is given). HSI then "commenced a covert operation using the online alias account" to identify users trying to purchase illegal weapons.

An AFP spokesperson would not comment on the specific dark web market, or markets, involved in the operation. But Gwern Branwen, a security researcher who has been following this story since April, believes that he has identified the market and the user account of the arrested weapons seller that was commandeered by HSI. He laid out his evidence on the DarkNetMarkets sub-Reddit.