Snowden has presented us with choices on how we want to move forward into the future. We're at a crossroads and we still don't quite know which path we're going to take. Without Snowden, just about everyone would still be in the dark about the amount of information the government is collecting. I think that Snowden has changed consciousness about the dangers of surveillance.

There are people who are always going to try to engage in activity that is illegal and they're going to try to subvert surveillance. But everybody should not give up their liberties and rights to privacy because some people are going to [do that]. We shouldn't stop or limit our basic liberties because some people are going to engage in criminal activities.

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.

The fact that the CIA knew that two of the 9/11 hijackers were entering the United States and didn't notify the FBI and that nobody lost their job is shocking. Instead, we occupied Iraq, which had nothing to do with 9/11. I mean, how did those choices get made?

One of the most frightening things, I think, is the capacity for retroactive searching, so you can go back in time and trace who someone is in contact with and where they've been.

People are starting to understand that the devices we carry with us reveal our location, who we're talking to, and all kinds of other information.

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?