Tor networking long has been considered to be the most secure networking protocol available. (See my earlier article, What is TOR and How Does It Work?, at http://goo.gl/WpZ3RI.) However, US government-paid hackers, funded by the Department of Defense (DoD), were able to break into Tor networking and find the true IP address of Brian Farrell, a man accused of being part of the Silk Road 2.0 team in the Dark Web.
A judge has confirmed (details available at https://assets.documentcloud.org/documents/2719591/Farrell-Weds.pdf) that researchers from Carnegie Mellon University were funded by the US government to develop ways to identify and track Tor users. The security vulnerability was patched as soon as the organization that supports Tor learned of it. Tor again is secure from all known attacks but who knows what the future will bring?
You can read the full story about the government-funded security breach in an article by Charlie Osborne on ZDNet at http://www.zdnet.com/article/judge-confirms-cmu-researchers-were-paid-to-unmask-tor-users.