Did you know that dark space "Tor was originally designed by the US Naval Research Laboratory, and continues to receive funding from the US State Department.(?) It is [still] used by the military, activists, businesses and others to keep communications confidential and aid free speech." It is also used by others who want to conduct business or communications in privacy, including criminals and those in countries denied the ability to freely communicate.
Both NSA and GHQ (UK security agency) are looking for loopholes to undermine Tor. Tor administrators are being notified monthly via "anonymous bug reports" that Tor needs to fix certain weaknesses to avoid being infiltrated by these national security agencies. Tor leadership believes that based on the sophisticated level of technical skill required to find, understand, and report on these weaknesses, that at least some of the reports are coming from technical staff within the agencies who are still mad that many innocent Americans and British are being spied on by their own government, as reported by Snowden. Read more about it here http://www.bbc.com/news/technology-28886462