[nounaut]

I think you mean to say that users of Tor are potentially vulnerable to NSA and GCHQ attacks. Specifically, they lack the capability to deanonymize individual targets upon request and according to the slides leaked by Snowden they are only able to deanonymize a very small fraction of the traffic and usually have to rely on attacking surrounding software, such as the Firefox browser bundled with Tor.

http://www.theguardian.com/world/2013/oct/04/nsa-gchq-attack...