A fifth of GCHQ intelligence comes from hacking in to phones and computers, the agency has revealed, as it won a human rights victory over its once secret technique.
The spy agency admitted last year that it regularly hacks electronic devices – known as equipment interference – to gather data on suspects.
It was forced to defend the power before the Investigatory Powers Tribunal after a civil liberty group and Internet companies claimed it breached human rights laws.
But the panel, which hears challenges against the security and intelligence agencies, ruled the methods were lawful.
In submissions to the hearing, it emerged that in 2013 around 20 per cent of GCHQ’s intelligence reports contained information derived from hacking.
The tactic, also known as computer network exploitation, allows authorities to interfere with electronic devices such as smartphones, tablets and PCs in order to obtain data.