At the time of its takedown AlphaBay, which had been in operation for over two years, had more than 250,000 listings for illegal drugs and toxic chemicals, and more than 100,000 listings for stolen and fraudulent identification documents, hacking tools and firearms, according to Europol.
Attorney General Jeff Sessions said, "The ability of these drugs to so instantaneously end these promising lives is reminder to us of just how incredibly risky these synthetic opioids are, especially when purchased anonymously from dark spaces on internet, and this is likely one of the most important criminal investigations of this entire year".
Jeff Sessions, U.S. Attorney General, said the AlphaBay network was among the most prolific drug suppliers.
According to Sessions, the US worked with officials in Thailand, the Netherlands, Lithuania, Canada, the UK, France, and Germany in shutting these markets down.
Law enforcement officials have struggled for years to crack down on these marketplaces, which are hard to locate because their software is distributed across the Tor network, which anonymises users and makes them nearly impossible to track.
Dark web vendors are enabling the circulation of illegal weapons already on the black market in addition to offering customers "better performing, more recent firearms for the same, or lower, price, than what would be available on the street", the report said.
Dutch National Police - aided by Europol and other European agencies - are said to have taken control of Hansa on June 20th, and monitored activities until it was shut down today.
In the wake of AlphaBay going offline, security experts predicted many users would flock to alternative marketplaces, including the world's then-largest darknet marketplace, called Hansa.
Updates on the Presidential Elections and Monsoon Session
The Monsoon Session of Parliament will commence from Monday, the day voting for the presidential election is slated to take place. The Congress said it stands with the government on matters of territorial integrity and national security.
AlphaBay ran like a normal online shopping site, allowing users to create login names and passwords and to search by category or name. Visitors to the online marketplace paid through digital currencies such as Bitcoin.
Thai authorities on July 5 arrested a 25-year-old Canadian citizen, Alexandre Cazes aka Alpha02 and Admin, on behalf of the US. "You can not hide. We will find you". That makes it 10 times bigger than the Silk Road drug bazaar that ended with its founder's arrest in 2013, the USA said.
AlphaBay went offline on July 4.
U.S. attorney general Jeff Sessions said: "The dark net is not a place to hide".
Federal agents said they seized millions in cryptocurrency and a huge stash of luxury goods, including homes, boats and sports cars they said were all purchased by Cazes and his wife using profits from AlphaBay.
The law enforcement operation was aimed at gathering as many new leads as possible and maximizing confusion within the darknet drug-buying community, according to Dutch cybercrime prosecutor Martijn Egberts.
Researchers based their report on investigations into 18 websites that operate on the dark web, the portion of the web not indexed by search engines and meant to be accessed with specialized software that makes it hard to identify their operators and visitors.