U.S.-based social media have become “command-and-control networks” for terrorists and criminals, and tech companies are in denial about their misuse, the new head of Britain’s electronic eavesdropping agency said.

Writing in Tuesday’s Financial Times, GCHQ chief Robert Hannigan said British intelligence agencies know that IS extremists use messaging services like Facebook, Twitter and WhatsApp to reach their peers with ease. He said spy agencies need to have greater support from the U.S. technology companies which dominate the Web in order to fight militants and those who host material about violent extremism and child exploitation.

“However much (tech companies) may dislike it, they have become the command-and-control networks of choice for terrorists and criminals.” he wrote.

Twitter declined to comment on the story. Facebook — which owns WhatsApp — had no immediate comment.

Yet the problem is larger than the question of social media, said Thomas Rid, professor of security studies at King’s College London. Companies like Apple, cognizant of the privacy concerns of its customers, are installing powerful encryption programs on their devices. That leaves agencies like GCHQ facing the onset of encryption on a massive scale.

“You cannot make the Internet super safe and keep it unsafe for pedophiles and terrorists,” Rid said of GCHQ’s dilemma.

Although Edward Snowden’s leaks have focused the world attention on the mass surveillance powers of the National Security Agency, Snowden has accused GCHQ of being far more aggressive.

Hannigan said intelligence agencies need to enter the public debate about privacy.

Eva Galperin of the Electronic Frontier Foundation, an online privacy group that is partly funded by tech companies, told BBC radio that intelligence agencies’ “powers are already immense. I think that asking for more is really quite disingenuous.”

(AP)