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.

I think it's radical to censor information because the government asks you to. That's radical.

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.

I think one of the most shocking things is how little our elected officials knew about what the NSA was doing. Congress is learning from the reporting and that's staggering. Snowden and [former NSA employee] William Binney, who's also in the film as a whistleblower from a different generation, are technical people who understand the dangers.

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.

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.

The most striking thing Snowden has revealed is the depth of what the NSA and the Five Eyes countries [Australia, Canada, New Zealand, Great Britain, and the US] are doing, their hunger for all data, for total bulk dragnet surveillance where they try to collect all communications and do it all sorts of different ways. Their ethos is "collect it all."