Thursday's takedown of the Silk Road 2.0 drug website was part of a much bigger crackdown by police in a dozen countries that seized more than 400 darknet domains, it was widely reported Friday.

Operation Onymous, as the coordinated international effort was dubbed, confiscated $1 million in bitcoins, $250,000 in cash, and a variety of drugs, gold, and silver, the Associated Press reported. In all, according to Wired, police seized 414 .onion domains, the Web addresses that use the Tor anonymity service to hide the physical location where they're hosted. At least 17 people were arrested. Sites besides Silk Road 2.0 that were taken down included Hydra, Cloud Nine, Pandora, and Blue Sky.

In all, some 55 different markets will be shut down once Operation Onymous is completed. Sites Agora and Evolution aren't among them. The rise of underground bazaars selling illicit drugs and services has continued despite last year's arrest of Ross William Ulbricht, the alleged mastermind of the original Silk Road who has pleaded not guilty and continues to fight the criminal charges in court.

The ability of police to track down and seize so many darknet sites is bound to generate some questions about the reliability of Tor, the system that allows end users and website operators alike to use Internet-connected computers without a traceable IP address. Troels Oerting, the head of the European Cybercrime Center, declined to tell Wired how the anonymous sites were located. At this early stage, there's no compelling reason to believe authorities know of a reliable way to bypass Tor. Given the numerous opsec blunders accused Silk Road 2.0 operator Blake Benthall is alleged to have made—including, authorities said, using his personal e-mail address to register servers that ran the site and hiring an undercover federal agent to help administer it—the most simple explanation is that investigators capitalized on similar errors made by other darknet operators.