US tech firms must help stop exploitation by militants: UK spy chief

 The new director of Britain`s surveillance agency GCHQ says US technology companies have become "the command and control networks of choice for terrorists" and must do more to help the work of security and law enforcement agencies.

Washington: The new director of Britain`s surveillance agency GCHQ says US technology companies have become "the command and control networks of choice for terrorists" and must do more to help the work of security and law enforcement agencies.

Robert Hannigan said Islamic State, more than any militant group before, was using mobile technology and social media such as Twitter Inc , Facebook Inc and WhatsApp to spread its message while hiding behind complex encryption tools, posing a greater challenge than ever to security services.

"GCHQ and its sister agencies, MI5 and the Secret Intelligence Service, cannot tackle these challenges at scale without greater support from the private sector, including the largest US technology companies which dominate the web," he wrote in an article for the Financial Times.