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.

No one would argue that it's in the United States' interest to have independent knowledge of the plans and intentions of foreign countries. But we need to think about where to draw the line on these kind of operations so we're not always attacking our allies, the people we trust, the people we need to rely on, and to have them in turn rely on us.

From the very beginning, I said there are two tracks of reform: there's the political and the technical. I don't believe the political will be successful, for exactly the reasons you underlined. The issue is too abstract for average people, who have too many things going on in their lives.

The new iPhone has encryption that protects the contents of the phone. This means if someone steals your phone - if a hacker or something images your phone - they can't read what's on the phone itself, they can't look at your pictures, they can't see the text messages you send, and so forth. But it does not stop law enforcement from tracking your movements via geolocation on the phone if they think you are involved in a kidnapping case, for example.

That's the key - to maintain the garden of liberty, right? This is a generational thing that we must all do continuously. We only have the rights that we protect. It doesn't matter what we say or think we have. It's not enough to believe in something; it matters what we actually defend.

Candidates run for election on campaign promises, but once they're elected they renege on those promises, which happened with President [Barack] Obama on Guantánamo, the surveillance programs and investigating the crimes of the Bush administration. These were very serious campaign promises that were not fulfilled.

When Laura Poitras asked me if she could film our encounters, I was extremely reluctant. I’m grateful that I allowed her to persuade me. The result is a brave and brilliant film that deserves the honor and recognition it has received. My hope is that this award will encourage more people to see the film and be inspired by its message that ordinary citizens, working together, can change the world.