The operation resulted in the seizure of more than $1 million in bitcoins, $250,000 in cash, drugs, gold, silver and weapons and computers.

The BBC has a report on arrests in Ireland. The Telegraph reports on arrests in Britain. German prosecutors say they will hold a press conference on the results on Tuesday.

TOR was apparently not an obstacle. But no one is talking about how they did it. WIRED reports:

Asked how Operation Onymous located the sites, Europol’s Oerting was unapologetically secretive. “This is something we want to keep for ourselves,” he said. “The way we do this, we can’t share with the whole world, because we want to do it again and again and again.”

Oerting sounds a bit cocky about the whole thing:

“This is just the beginning of our work. We will hunt these sites down all the time now,” he said, praising the cooperation of all the international law enforcement agencies involved. “We’ve proven we can work together now, and we’re a well-oiled machine. It won’t be risk-free to run services like this anymore.”

While there will be questions about whether TOR has a security vulnerabilty, it's too early to make any judgments. WIRED reports other law enforcement techniques may have been used. Some suspect the feds used malware. Other thoughts are gathered in this Forbes article.

Europol's announcement is here. Law enforcement agencies that participated in Operation Onymous include:

Europol’s European Cybercrime Centre (EC3), the FBI, the U.S. Immigration and Customs Enforcement’s (ICE), Homeland Security Investigations (HSI) and Eurojust.

Other countries participating: Bulgaria, the Czech Republic, Finland, France, Germany, Hungary, Latvia, Lithuania, Luxembourg, the Netherlands, Romania, Spain, Sweden and Switzerland

The takedowns seem to be part of Project ITOM (Illegal Trade on Online Marketplaces). Some official documents on it were provided to the Dutch media in September. Here's one from the Dutch Public Prosecutor's Office, (Via Google transator):

Project ITOM has the following operational pillars:

1. punishment and deterrence, by discouragement of sellers and administrators. There are in addition to buy even more pseudo identification possibilities. Tearing down hidden services (market places) if identified. For this first pillar, the below listed countries met several times already in the Hague, and the coming months will be the first internationally coordinated actions are performed.

2. approach through the logistics process. Purchased goods are sent via regular mail and packet flows. This offers opportunities for the erection of barriers: increasing detection opportunities and make it more difficult to send illegal goods by post. This section of the criminal modus operandi also offers many starting points for the detection. For this second pillar works closely with the Dutch customs and the LP is an operational meeting early next year with European customs and postal and parcel companies organized to identify intervention possibilities and operational arrangements.

3. the third pillar focuses on the payment process with cryptocurrencies; now mainly the Bitcoin. Also those payments leaving a trail of information behind, even though they seem to be completely anonymous. In addition you can with your Bitcoin still few payments so there is great demand for anonymous Exchange capabilities of Bitcoins to normal currency. Also this bottleneck is to detect a gold mine. In addition, new regulations - those within ITOM is supercharged -make it possible to get more visibility on Bitcoin transaction.

The project is funded by the European Commission. In addition to Netherlands (LP, customs, DLR, FIOD and FP), inter alia, the following countries and organisations take part: Europol, Eurojust, the U.S. (FBI and ICE), Germany (BKA and public prosecutors ' offices Hessen and Celle), Portugal (PGdR), the UK (NCA), Sweden (Bureau of Investigations), Estonia, Finland (Customs), Italy, Spain, France (Customs), Latvia, Lithuania, Poland, Austria, etc.

In related news, Pirate@40, aka Trendon Shavers, the founder of Bitcoin Savings and Trust was charged yesterday with wire fraud and securities fraud for an alleged Bitcoin Ponzi scheme. The Complaint is here.