http://34reqsy6tqou6avwrkm23s4mpkrwz3drtq2e5yr7sywi76h7plnaahad.onion/articles/botnet.xhtml
The FBI has even paid a university to deanonymize TOR users (archive) , and that's how Silk Road 2.0's owner could be locked up. This is just what we know about - more attacks are surely in use or preparation. TOR still relies on its encryption, and if that's ever broken - say goodbye to your anonymity, since all the traffic is stored for possible future decryption.