Seventeen people have been arrested in a series of coordinated raids on underground websites selling illegal drugs, a top Europol official said Friday, in one of the largest crackdowns on the so-called "Darknet" to date.
Dutch prosecutors said the arrests were made in the U.S., Ireland and Germany.
Troels Oerting, head of the European police agency's cybercrimes division, said it coordinated police operations in more than a dozen countries on Thursday from its headquarters in The Hague, Netherlands. The raids included a U.S. operation in which the FBI announced the arrest in San Francisco of a man accused of running the Silk Road 2.0 online bazaar, where drugs including Ecstasy, cocaine and LSD were sold openly.
"We will go after drug dealers regardless of whether they operate in the physical or virtual world," Oerting said.
Europol said in addition to the Silk Road site, it has seized or shut down numerous other virtual marketplaces with names such as Hydra, Cloud Nine, Pandora and Blue Sky. Police seized $1 million (800,000 euros) in digital currency and $225,000 worth of cash, drugs, gold and silver.
Silk Road and similar websites are not visible on the open Internet. They can only be accessed with special browsers that encrypt web traffic for transfer via the TOR network of anonymizing servers — the Darknet. Buyers and sellers on the sites trade using digital currencies, usually Bitcoin.
"I think there will be more than 55 different markets shut down" when the operation is finished, Oerting said. "We didn't get (major sites) Agora or Evolution, because there's only so much we can do on one day."
Markets on the Darknet have flourished since the closure of the original Silk Road in October 2013. At that time police arrested Ross Ulbrecht on suspicion of operating the site under the moniker "the Dread Pirate Roberts." Ulbrecht says he is innocent of wrongdoing.
The FBI said Thursday it had arrested 26-year-old Blake Benthall on suspicion of running the Silk Road 2.0 site, which was launched weeks after the first Silk Road closed.
Benthall is expected to appear in a New York federal court Friday.
Europol head Oerting declined to give more information on arrests in other countries because he said investigations are continuing.
"In the next wave we're going to come after people using these sites," he said. "They might hear a knock at the door."
He could not confirm whether any firearms or child pornography have been seized in any of the raids. He said libertarian arguments that online markets reduce violent drug-related crime are wrong, as the violence merely goes unseen.