Coordinated raids by law enforcement agencies in the U.S. and 16 European countries have closed hundreds of underground websites, including dozens dealing in weapons and drugs, and led to the arrest of 17 people.
The raids took place on Thursday and were the biggest so far against sites running on the Tor network, according to the U.S. Department of Justice and Europol, which cooperated on the action.
Tor is an encrypted system that facilitates anonymous communication. It has plenty of legitimate uses, particularly for evading surveillance in countries with authoritarian governments, but its use by criminals has caused controversy. Police have increasingly been targeting underground websites on Tor, and Thursday's raids are the latest in that work.
Troels Oerting, head of Europol's European cybercrime center, said criminals using Tor have long considered themselves beyond the reach of the law, but that's no longer the case.
"We can now show that they are neither invisible nor untouchable," he said in a statement. "The criminals can run but they cant hide."
The list of shuttered sites included names such as Blue Sky, Hydra and Cloud Nine, and the DOJ said they dealt in drugs, fake currency, stolen credit card data and fake ID documents. Executive Outcomes dealt in firearms and shipped worldwide, Fake Real Plastic sold counterfeit credit cards, Fake ID sold fake passports and Fast Cash and Super Notes Counter sold counterfeit Euro and U.S. currency in exchange for bitcoins, authorities said.
The first hint of the raids came on Thursday, when police in the U.S. said they had arrested the alleged operator of Silk Road 2.0, a website allegedly used to sell illegal drugs, computer-hacking tools and fraudulent identification documents. At the time they didn't say that the arrest was part of a larger action.
"As illegal activity online becomes more prevalent, criminals can no longer expect that they can hide in the shadows of the dark web,'" said U.S. Attorney Preet Bharara, in a statement. "We shut down the original Silk Road website and now we have shut down its replacement, as well as multiple other dark market sites allegedly offering all manner of illicit goods and services, from firearms to computer hacking."
But despite the assertions of Oerting and Bharara, it still remains incredibly difficult for law enforcement to discover who is behind a Tor website. The same safeguards built into the system that keep the identity of a dissident secret from a government also help criminals stay anonymous. Typically, a true identity is discovered because of a clue such as an email address that has inadvertently been left in the open.
Martyn Williams covers mobile telecoms, Silicon Valley and general technology breaking news for The IDG News Service. Follow Martyn on Twitter at @martyn_williams. Martyn's e-mail address is martyn_williams@idg.com