Didn't the Russian government just put a bounty on doing this? www.bloomberg.com/news/2014-07-29/p...nonymous-internet-usage-in-russia-surges.html
Wilders has a thread covering it: http://www.wilderssecurity.com/threads/hackers-promise-to-break-tor-on-a-3-000-budget.365766/ It's not Tor itself, the attacks are always web browser based or rouge relays. https://blog.torproject.org/blog/tor-security-advisory-relay-early-traffic-confirmation-attack