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.

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.

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.

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.

Just consider the CIA and its effort to suppress the Senate's review of its torture program. Take in the fact that we live in a country that a) legalized torture and b) where no one was ever held to account for it, and now the government's internal look at what happened is being suppressed by the CIA. That's a frightening landscape to be in.

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?

When the most important decisions are made in secret, we lose our ability to check the powers that control.