London Guardian 
December 30, 2013
A top-secret National Security Agency hacking unit infiltrates computers around the world and breaks into the toughest data targets, according to internal documents quoted in a magazine report on Sunday.
Details of how the division, known as Tailored Access Operations (TAO), steals data and inserts invisible “back door” spying devices into computer systems were published by the German magazine Der Spiegel.
The magazine portrayed TAO as an elite team of hackers specialising in gaining undetected access to intelligence targets that have proved the toughest to penetrate through other spying techniques, and described its overall mission as “getting the ungettable”. The report quoted an official saying that the unit’s operations have obtained “some of the most significant intelligence our country has ever seen”.
NSA officials responded to the Spiegel report with a statement, which said: “Tailored Access Operations is a unique national asset that is on the front lines of enabling NSA to defend the nation and its allies. [TAO’s] work is centred on computer network exploitation in support of foreign intelligence collection.”