Police have arrested 17 people in an international crackdown on underground websites selling drugs, but a version of the most well-known drug market is already back online.

In a statement Friday, the European policing agency said it co-ordinated raids a day earlier with U.S. law enforcement agencies, which announced on Thursday the arrest in San Francisco of Blake Benthall, who is accused of running the Silk Road 2.0 online drug market.

But within hours of the raids, a new version of Silk Road, called “Silk Road Reloaded,” was online.

The new version already has hundreds of listings for a variety of drugs, as well as a handful of other illegal goods and services.

On Thursday and Friday, police in 16 European countries shut down several other marketplaces in addition to Silk Road and seized $1 million in digital currency and $225,000 in cash and drugs, Europol said.

The U.K. National Crime Agency said Friday that the raids had targeted 400 “dark web sites.”

In the U.K., police have arrested six people in England and Wales, who were allegedly involved in selling drugs online. All have been released on bail.

Silk Road and similar websites are not visible on the open Internet, and can only be accessed with browsers that encrypt web traffic.

Buyers and sellers trade using encrypted digital currencies, usually Bitcoin.

Other markets that appear to have been closed include Cloud 9, which sold drugs

Silk Road 2.0 went online in November 2013, weeks after American police seized the original Silk Road website and arrested its alleged administrator, Ross Ulbricht.

Ulbricht, who used the alias Dread Pirate Roberts online, was replaced by a second person calling him or herself Dread Pirate Roberts. That person has not been arrested.

In December 2013, police raided the new Silk Road, taking the website offline and arresting two alleged employees.

The FBI allege Benthall assumed control of the site after that raid.

Benthall, who allegedly identified himself on Silk Road as Defcon, worked briefly for aerospace company SpaceX, the company told NBC News on Friday.

According to his LinkedIn profile, he works at Codespike, a San Francisco-based tech startup that builds applications and digital products.

In the criminal complaint against Benthall, the FBI said that by October 2014 Silk Road was processing about $8 million in sales for 150,000 users every month, which brought about $400,000 in commission to the website’s operators.

The FBI also alleges that Benthall bailed out Silk Road with 1,000 of his own Bitcoin — equivalent to about $476,000 (U.S.) at the time — after someone stole about $1.4 million from the website’s Bitcoin wallet.

Shortly after the December raid, an undercover Homeland Security agent was hired as a Silk Road staff member, the FBI said in the criminal complaint.

The agent gained access to closed areas of the site where Defcon and staff discussed Silk Road’s operations, and also received from Defcon regular Bitcoin payments, the FBI said.

The FBI complaint, filed Oct. 29, alleges Benthall made several operational security mistakes that allowed police to track him.

In May 2014, police in an unidentified country that is not the U.S. were able to make a copy of a server that the FBI had identified as the host for Silk Road.

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On that server, the FBI found logs of online conversations between a person they believed to be Benthall and someone identified as “captain,” who they allege was the second Dread Pirate Roberts.

The FBI also said that information on the server revealed it had been maintained for some time by a person using the email account “blake@benthall.net .”

That address was also used on Benthall’s personal page on GitHub, a social network for software developers.

The FBI received a copy of Benthall’s entire email account from Google, which included “numerous emails” in which the sender identifies himself as Benthall.

In Benthall’s inbox, the FBI also said they found an email Benthall allegedly sent to himself, which included links to private messages on the Silk Road forum that would have been visible only to registered members.

When police took the site offline to copy it in May 2014, the Silk Road server sent a series of automated notices to that email account.

In June, the FBI said, someone sent several urgent emails to the company maintaining the Silk Road server, saying the server was not working properly.

The emails came from a person using an IP address that the FBI later tied to a hotel in South Lake Tahoe, Calif.

Benthall was allegedly a guest at that hotel at the time.

A geo-tagged post to Benthall’s public Instagram profile, which was also shared on his Twitter, appears to confirm that he was in South Lake Tahoe in early June.

In the emails, the person claimed that the server held “highly confidential client data” that, the email implied, was in some way related to the international arms trade.

On the day Silk Road 2.0 went online, Benthall also shared on his public Twitter account a tweet that read “All this talk about the #SilkRoad being back up just makes me want to watch #ThePrincessBride,” referring to the film from which alleged Silk Road administrator Ulbricht drew his Dread Pirate Roberts alias.

Other emails revealed that Benthall sold the equivalent of about $25,000 in Bitcoin, and later used Bitcoin to put a $70,000 down payment on a Tesla Model S electric car, the FBI said.

With files from The Associated Press

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