US tech giants are helping terrorists, new chief of UK spy agency says

Twitter and Facebook are so important to militant groups that the technology giants should give security services greater access to their networks to allow governments to foil attacks, the new head of Britain's surveillance agency said.

Privacy has never been "an absolute right", according to the new director of GCHQ, who has used his first public intervention since taking over at the helm to accuse US technology companies of becoming "the command and control networks of choice" for terrorists.

Robert Hannigan said a new generation of freely available technology has helped groups like such as Islamic State to hide from the security services and accused major tech firms of being "in denial".

He also went further than his predecessor, Iain Lobban, in seeking to claim the leaks of Edward Snowden have aided terror networks.

"The Isis leadership understands the power this gives them with a new generation," Hannigan said, adding that militants had used World Cup and Ebola hashtags on Twitter messages to pitch their views to a wider audience.

"The extremists of Isis use messaging and social media services such as Twitter, Facebook and WhatsApp," he said.

GCHQ and sister agencies including MI5 could not tackle those challenges without greater support from the private sector, "including the largest US technology companies which dominate the web", Hannigan argued in an opinion piece published by the on Monday, just days into his new job.