A coordinated effort by law enforcement globally has taken down one of the baddest, most notorious hacker forums on the so-called “Dark Web”: the Darkode forum.

To put this in perspective, Darkode is the only English-speaking cybercriminal forum to hold its own among the slew of Russian sites that form the marketplace for most of today’s organized cybercrime. It was a den of cyber-iniquity in many ways, offering a place for members to trade and barter their hacking expertise, malware, credit card and bank credentials, botnets-for-rent and DDoS-for-hire. It ranked in the top five of the most prolific criminal forums worldwide, and was the place that represented the most danger to the U.S.

“Of the roughly 800 criminal internet forums worldwide, Darkode represented one of the gravest threats to the integrity of data on computers in the United States and around the world and was the most sophisticated English-speaking forum for criminal computer hackers in the world,” said U.S. Attorney David Hickton.“Through this operation, we have dismantled a cyber-hornets’ nest of criminal hackers which was believed by many, including the hackers themselves, to be impenetrable.”

Led by the Feds and Europol, the takedown resulted in 28 arrests, 37 house searches and numerous seizures of computers and other equipment across the globe—including one 20-year-old kid here in the U.S. By day, he’s a sophomore at Carnegie Mellon and a FireEye security intern; by night (or whenever), he’s the mastermind behind the Dendroid malware, which can be used by those with limited coding expertise to infect and trojanize any Android app, turning it into a tool for spying or data exfiltration.

Darkode was an exclusive venue: There were only about 250-300 active users. Membership was by invitation only, and after being vetted by a trusted member of the forum.

“Although there were several scandals, changes and rumors of the forum being compromised during the course of its existence, the Darkode forum was the place to go to if you were an English-speaking cybercriminal,” Europol added.

The international coordinated action had the involvement of law enforcement officers from 20 countries from the European Union and beyond.

 “Today’s global action caused significant disruption to the underground economy, and is a stark reminder that private forums are no sanctuary for criminals and are not beyond the reach of law enforcement,” said Europol director Rob Wainwright. “We will continue to work with our law enforcement partners to make cyberspace as crime-free as possible for the world’s citizens.”