You simply have to eventually fall under suspicion from somebody even by a wrong call. And then they can use this system to go back in time and scrutinize every decision you've ever made, every friend you've ever discussed something with. And attack you on that basis to sort to derive suspicion from an innocent life and paint anyone in the context of a wrongdoer.

The United States is more reliant on the technical systems. We're more reliant on the critical infrastructure of the internet than any other nation out there. And when there's such a low barrier to entering the domain of cyber-attacks we're starting a fight that we can't win.

If you ask anybody at Cyber Command or look at any of the job listings for openings for their positions, you'll see that the one thing they don't prioritize is computer network defense. It's all about computer network attack and computer network exploitation at Cyber Command.

I believe that when [senator Ron] Wyden and [senator Mark] Udall asked about the scale of this, they [the NSA] said it did not have the tools to provide an answer. We do have the tools and I have maps showing where people have been scrutinised most. We collect more digital communications from America than we do from the Russians.

Increasingly we're seeing these ultra-partisan sites getting larger and larger readerships because people are self-selecting themselves into communities.

You can't come up against the world's most powerful intelligence agencies and not accept the risk. If they want to get you, over time they will.

If we can't have an open and honest debate about the value of ideas in a university in Glasgow, or Boston, or anywhere else in the world, then where are they going to go?