It wasn’t ever seriously in doubt, but the FBI yesterday acknowledged that it secretly took control of Freedom Hosting last July, days before the servers of the largest provider of ultra-anonymous hosting were found to be serving custom malware designed to identify visitors. […]
Freedom Hosting was a provider of turnkey “Tor hidden service” sites — special sites, with addresses ending in .onion, that hide their geographic location behind layers of routing, and can be reached only over the Tor anonymity network. Tor hidden services are used by sites that need to evade surveillance or protect users’ privacy to an extraordinary degree – including human rights groups and journalists. But they also appeal to serious criminal elements, child-pornography traders among them. […]
http://www.wired.com/threatlevel/2013/09/freedom-hosting-fbi/