AlphaBay's takedown was led by the USA and involved cooperation by law enforcement around the world: Thailand, the Netherlands, Lithuania, Canada, the United Kingdom, and France all pitched in, as well as the European law enforcement agency Europol.
AlphaBay mysteriously went offline earlier this month, prompting speculation among its users that authorities had seized the site.
According to a U.S. indictment opened Thursday, Cazes created AlphaBay in July 2014 to host, via the anonymizing Tor network, a wide range of illicit trade and money laundering.
Europol said the coordinated law enforcement action in Europe and the U.S. makes it "one of the most sophisticated takedown operations ever seen in the fight against criminal activities online".
"The dark net is not a place to hide", Sessions said.
"This is likely one of the most important criminal investigations of the year - taking down the largest dark net marketplace in history", he added.
AlphaBay itself operated for more than 2 years and eclipsed the previous titleholder for the largest online illegal market, Silk Road, which was shut down in 2013.
Two weeks and a day after the arrest of Alexandre Cazes, 25 years old, a He that led the big life in Thailand, the u.s. department of justice shed some light on this matter. The take-down of the two largest criminal dark web markets in the world by European and American law enforcement authorities shows the important and necessary result of global cooperation to fight this criminality.
Dutch authorities were able to take control of the Hansa site on June 20 and allowed it to continue operating in order to gain information about those using it to traffic illegal drugs and weapons.
Cazes had set up a site that allowed you to buy and sell anonymously on the Internet of hard drugs such as fentanyl and heroin, forged documents, even chemicals and firearms.
Sessions added that United States security groups had attributed a number of drug-related deaths to substances sold via the sites.
Cazes had been charged in a 16-count indictment with conspiracy to: commit identity theft, engage in racketeering, distribute narcotics, commit access device fraud, and launder money.
"I have the honor of serving as attorney general", he said.
When police in Thailand raided Cazes' Bangkok home, they found his laptop "unlocked and unencrypted" and logged in with his purported administrator's account.