We've already seen shifts happening in some of the big companies - Google, Apple - that now understand how vulnerable their customer data is, and that if it's vulnerable, then their business is, too, and so you see a beefing up of encryption technologies. At the same time, no programs have been dismantled at the governmental level, despite international pressure.

In terms of sources coming forward, I really reject this idea of talking about one, two, three sources. There are many sources that have informed the reporting we've done and I think that Americans owe them a debt of gratitude for taking the risk they do.

In all my work, I'm interested in trying to understand the human consequences of government policies.

We don't stand here alone, it's possible through the great organisations that support us. The disclosures that Edward Snowden revealed aren't only a threat to privacy but to democracy, when the most important decisions made affect all of us. Thank you to Edward Snowden. I share this with Glenn Greenwald and other journalists who are exposing truth.

Snowden is almost preternaturally prepossessing and self-possessed. I think of a novelist whose dream character just walks into his or her head. It must have been like that with you and Snowden. But what if he'd been a graying guy with the same documents and far less intelligent things to say about them? In other words, how exactly did who he was make your movie and remake our world?

So my first experience was that I had to do a reboot of my expectations. Like fantastic, great, he's young and charismatic and I was like wow, this is so disorienting, I have to reboot. In retrospect, I can see that it's really powerful that somebody [Snowden] so smart, so young, and with so much to lose risked so much.

From a personal perspective, because I'm on a watchlist and went through years of trying to find out why, of having the government refuse to confirm or deny the very existence of such a list, it's so meaningful to have its existence brought into the open so that the public knows there is a watchlist, and so that the courts can now address the legality of it. I mean, the person who revealed this has done a huge public service and I'm personally thankful.