While Tor is generally thought of as a place where those who want their online activity to remain anonymous, a new report suggests the FBI has been successfully tracking users across the network for some time. 

Law enforcement agents were able to pin point a number of Tor users attached to the Aaron McGrath child pornography case in 2012. After obtaining warrants to track certain individuals accessing McGrath's servers, agents were able to pull exact home addresses and users names by infecting the servers with a form of malware. The tracking software identified the IP address of as many as 25 individuals in this case.

The malware tactic doesn't necessarily shut down the Tor system at its core, but instead side steps it in order to plant the tracking software on particular servers. The FBI has been able to tap users within the Tor network previously, but not with the same level of control an ease as we now know they were in the McGrath investigations.

The tactic is already stirring up controversy with civil liberty groups. The FBI has apparently remained coy about the operation's details past the allotted 30 days provided by the warrant. One legal expert told Wired that normally "someone who is subject to a search warrant is told virtually immediately,"  and then continued by saying "what I think you have here is an egregious violation of the Fourth Amendment." Some suggest the FBI is using the malicious software technique in much broader strokes than it may seem as well, causing innocent individuals to become infected with the government malware.