When I talk about the polling, I'm talking about the principles. It shows these officials are knowingly attempting to shift public opinion, even though they know what they say is not factual.

America is a fundamentally good country. We have good people with good values who want to do the right thing. But the structures of power that exist are working to their own ends to extend their capability at the expense of the freedom of all publics.

In the United States the White House has appointed two different independent panels who had full access to classified information for the last 10 years that master balance has been in place in the United States, and they found that despite intercepting the calls - everybody in the country, - it had never stopped a single terrorist attack. So the question is, why would these officials be pursuing these policies, if we know they don't work, if they don't stop terrorism?

It's important to remember when you start doing things like attacking hospitals through the internet, when you start attacking things like internet exchange points, when something goes wrong, people can die. If a hospital's infrastructure is affected, lifesaving equipment turns off.

Anyway, it's not true that the authorities cannot access the content of the phone even if there is no back door. When I was at the NSA, we did this every single day, even on Sundays. I believe that encryption is a civic responsibility, a civic duty.

Privacy is a function of liberty.

When we look at the full-on mass surveillance watching everyone in the country, in the United States, it doesn't work. It didn't stop the attacks in Boston. The marathon bombings. Where again, we knew who these individuals were. It didn't stop the Underwear Bomber, whose father walked into an embassy and warned us about this individual before he walked onto an airplane. And it's not going to stop the next attacks either. Because again, they're not public safety programmes. They're spying programmes. They are valuable for spying.