British spies have received government permission to intensively study software programs for ways to infiltrate and take control of computers. The GCHQ spy agency was vulnerable to legal action for the hacking efforts, known as “reverse engineering,” since such activity could have violated copyright law. But GCHQ sought and obtained a legally questionable warrant from the Foreign Secretary in an attempt to immunize itself from legal liability.

GCHQ’s reverse engineering targeted a wide range of popular software products for compromise, including online bulletin board systems, commercial encryption software and anti-virus programs. Reverse engineering “is essential in order to be able to exploit such software and prevent detection of our activities,” the electronic spy agency said in a warrant renewal application.