Which of your staff do you think is working for the CIA? Sean Varney

Ha, ha, ha! I suspect each and every one of them. As Ronald Reagan used to say, "Trust, but verify".

Do you think any of the heads of companies in the USA have changed their ways or views since you have been challenging them over the way they manage and conduct business? Steve Robbins

They now show my films in business ethics classes to business majors. Mostly, I think, as a means of how to avoid me, or somebody like me. I've seen direct change, there's been a direct effect from some of the things I've done. In my last documentary, The Big One, Phil Nike was forced to end child labour in his Indonesian shoe factories as a result of the film. So I do think it can have an impact, but these corporate titans will always go kicking and screaming into any sort of change that's good for the world.

In the US press, there have been many insinuations about your film's lack of "integrity", so to speak. Many reviewers feel you are taking advantage of victims to further your own agenda. How would you respond? Jeanne Savelle

That's correct. If I know what that means, it means I take advantage of Charlton Heston inviting me into his home, to interview him, because I have an agenda which is to stop people like Heston, who want to see to it that there's as many guns in people's homes as possible. How can that be a criticism? It's an odd criticism to make of the film. You would think you'd be complimented for doing that. I think all films take advantage of the situation they're in to make a good film.

Who finances the National Rifle Association, and is there any well-financed anti-gun lobby group in opposition to it in the USA? Mark Henderson

The NRA is financed by its four million members, by the gun lobby, by gun companies. The anti-gun groups have very little funding and have a hard time being effectual.

Some of the people in the NRA are very scary/stupid people with guns. Big guns. Are you not afraid for your life? I would be. Kyle

I'm never afraid of the bully, the bully wants you to be afraid. If you stand up to the bully - you remember this from when you were a little kid - the bully went some place else, cos you're too much work if you stand up to him. The bully needs you to be afraid, the bully thrives on your fear. If you cease to be afraid, the bully can't function, it disarms him. That's true on the playground or it's true with Gandhi. The power comes in not being afraid.

Do you own a gun? Laura

Just the gun that you see that I win at the bank, which I've got to get rid of.

Why is it that the American Left is traditionally fractured, rather than unified? James

We're afraid of success, we're afraid of this one basic truth: that the American public is actually in agreement with us, we're in the majority. That's uncomfortable, so we spend our time fighting with each other. The majority of Americans, and I'm sure the majority of Brits, support strong environmental laws, that's a liberal issue. The majority of Americans, the majority of Brits, are pro-choice when it comes to abortion, they're pro-women's rights. On the whole litany of liberal issues, the majority of our two countries are quite liberal on the issues, so why aren't we figuring out how to use this incredible time - when we don't have to convince the majority to be on our side, they're already there - why are we wasting it fighting each other, or doing nothing, or throwing in with people who are not really there to enact a true liberal, left, progressive agenda, like the Democrats in America or like Labour here... New Labour! Sorry about that.

I saw Bowling For Columbine at Cannes this year and, as with all your work, was enthralled. However after the showing I overheard a group of young Americans saying that they thought it was all a hoax and wondering how you set it all up. Is this a common reaction in America? If so, how do you feel you will ever get your message across to the people who need to hear it the most? Anne-Marie Newman

It's not a common reaction because the movie in its first four weekends is already setting records for a documentary in theatres all over the country. I heard they did a poll of people who went this past weekend in America to the movie, the majority said this was their first time ever in a movie theatre to see a documentary. So it's reaching a much wider audience than a usual documentary. I'm curious why those Americans would think it's a hoax. Do they think it's a hoax that we kill over 11,000 of each other each year? Do they think it's a hoax that there's a quarter of a billion guns in our homes? Those may be harsh truths for us to face. Do they think that we had nothing to do with the overthrow of democratically elected governments in Chile, Guatemala, and elsewhere through the years? I realise that this film is a bitter pill for a lot of Americans to swallow, I'm hoping that they take it, and swallow it, think about it, and do something about it.

Do you think the new wave of 'patriotism' in the US is also fuelling public fear and paranoia? Steven Wills

Yes, but I don't think this new wave of patriotism has taken hold. The largest selling non-fiction book of the year after 9/11 was a thing called Stupid White Men. How could that be if there was a wave of crazy patriotism? I believe I'm in the majority on these issues and that people in other countries need to see that all Americans are not behind George W Bush.

Apart from the fact that US gun laws allow it, why is it that US banks give you a free fire-stick when you open an account, whereas UK banks will give you a Wallace & Gromit piggy-bank? Are our societies so different? Peter Oliver

I’ve understood that there have been many piggy-bank murders, and piggy-banks have been used to slaughter hundreds of Brits throughout the years. I don't know why your banks give out these piggy-banks, and I think they should stop it.