The director of GCHQ has said that technology firms are "in denial" over the misuse of their products by the terrorist group Islamic State (IS).
Directing his ire at social networking firms such as Twitter, Facebook and its subsidiary WhatsApp, Robert Hannigan called for "better arrangements" to help police and spooks do their jobs.
Writing in the Financial Times, he said: "However much they may dislike it, they have become the command-and-control networks of choice for terrorists and criminals, who find their services as transformational as the rest of us."
He noted that IS, also known by the acronyms Isis and Isil, was unlike previous Islamic terror groups in that it is willing to operate outside of "dark spaces", often piggybacking on trending topics to spread its message.
"They have realised that too much graphic violence can be counter-productive in their target audience and that by self-censoring they can stay just the right side of the rules of social media sites, capitalising on western freedom of expression," he added.
In comments that mirror those of his counterpart at the US Federal Bureau of Intelligence (FBI), Hannigan warned that privacy "has never been an absolute right" and that GCHQ was happy to be part of a "mature debate" on the issue.
"I suspect most ordinary users of the internet are ahead of [technology firms]: they have strong views on the ethics of companies, whether on taxation, child protection or privacy; they do not want the media platforms they use with friends and families to facilitate murder or child abuse," he said.
"They know the internet grew out of the values of western democracy, not vice versa. I think those customers would be comfortable with a better, more sustainable relationship between the agencies and the technology companies."
