TORONTO -- "Haunting." That's how Oliver Stone describes what he knows about the National Security Agency's top secret surveillance operations and, he says, it's evidence that "the world is really out of control."

Joseph Gordon-Levitt, who plays Edward Snowden in the forthcoming biopic about the NSA whistleblower, is no less disturbed by the U.S. government's power to surreptitiously spy on the world, but is a little more optimistic about the future of privacy.

Stone, Gordon-Levitt and other cast members of "Snowden," which hits theatres on Sept. 16, spoke about their interactions with the exiled whistleblower and their views on privacy in the Internet age at a Toronto International Film Festival press conference Saturday.

Here are five things from the chat:

ON SNOWDEN'S PATRIOTISM

"He really was doing what he did out of a sincere love for his country and the principles the country was founded on," said Gordon-Levitt, who admitted he knew little about Snowden before Stone approached him to take on the role.

"I think it shows two different kinds of patriotism. There's the kind where you're allegiant to your country no matter what and you don't ask any questions. But there's another kind of patriotism -- that is what I really wanted to show in this character -- which is the kind of patriotism that he grows into over the course of the nine years that you see in this story, where he does ask questions and that's the privilege of being from a free country like the United States of America."

ON STONE'S INTEREST IN THE STORY

"This is really a secret underworld and no one in the NSA has come forward in its 70-year history," Stone said.

"We only saw a sliver until Ed Snowden. No one saw into that thing, so it's really an undercover detective story. And for me it's exciting because it's like JFK, it goes into something that we don't know. Americans don't know anything about it and they still don't because it's tricky.

"The government lies about it all the time and what they're doing is illegal and they keep doing it. And it gets better and better, what they do, so this a very upsetting story."

ON THE FUTURE OF PRIVACY

"Unfortunately, Edward Snowden has warned us, more than once, about privacy and he said very clearly it'll creep up and he says in the movie the next generation won't know what privacy is," said Stone.

"I grew up in a world that this never could've happened, I believed. I read George Orwell, never thought it could happen, and from 2001 on it's been very clear that something radical has changed. And you know me, I think there's more to it than meets the eye, because whatever they tell you you've got to look beyond the surface of things."

Gordon-Levitt said he's hopeful that the public will demand more of their governments and push back against encroachments on privacy.

"I completely think it's worth being very critical of some of these particular actions of the U.S. government, but I also choose to remain optimistic that we still do live in a country where we still do have the opportunity to raise our voices and try to take control of this."

WHY PEOPLE WILFULLY GIVE UP THEIR PRIVACY

"Some people really like being as public as they can about everything they're doing and they like sharing what they're thinking, what they're eating, what they're wearing, what they're doing, where they're going and I of course think that's everybody's choice," said Gordon-Levitt.

"I completely respect anybody's desire to sort of turn their life into a performance that way, if that's their preferred form of expression. I just think it's important that we all have the ability to make that choice."

WHAT THEY HOPE HAPPENS TO SNOWDEN

"There's options," said Stone, "you know Mr. Obama could pardon him and we hope so. We hope Mr. Obama has a stroke of lightning and he sees the way. (But) he's been one of the most efficient managers of this surveillance world. (This is) the most extensive, invasive surveillance state ever existed. He's created it, built it up, big money, rockets 200 miles in space, satellites that are peeking in as we speak -- 'Hi Barack!'-- so this is pretty serious.

"But he's created this world, so rationally, it doesn't figure. But we hope."

Added Gordon-Levitt: "I know he would love to come home, I hope for that."