AlphaBay and Hansa Market were successors to the first and most famous market operating on the so-called dark net, Silk Road, which the authorities took down in October 2013.
AlphaBay grew into a business with 200,000 users and 40,000 vendors — or 10 times the size of Silk Road — the Justice Department said Thursday.
The site recently come under scrutiny because many of its vendors sell synthetic opioids, like fentanyl, which play a central role in the nationwide overdose epidemic.
The authorities said 122 vendors had been advertising fentanyl on the site. The sale of such drugs on AlphaBay was detailed in a front-page article in The New York Times last month.
Hansa Market had about 1,800 vendors selling drugs of all sorts, the Dutch authorities said on Thursday.
“This is likely one of the most important criminal investigations of this entire year, I have no doubt about that,” Attorney General Jeff Sessions said at a news conference on Thursday. “Most of this activity was for illegal drugs, pouring fuel on the fire of the national illegal drug epidemic.”
AlphaBay went down in early July, prompting speculation that it had been seized by law enforcement authorities.
