Actor Charlie Sheen has hit out at critics who slammed him for expressing his controversial opinions on the 9/11 terrorist attacks. The SCARY MOVIE star appeared on a radio talk show last month (MAR06), saying he had trouble believing the "official" 9/11 story from US President George W Bush's administration and the 9/11 commission. He explains, "I just had a lot of questions. The forum I chose to voice those questions in was the Alex Jones radio show, just because he's a guy I had been a fan of and followed for a lot of years. "I got attacked. The reaction was pretty severe, 'He's not qualified.' 'Who the hell is he to have an opinion about something so horrible?' "It was sad because they didn't really take a look at any of the stuff I was asking them to look at, any of the evidence, or any of the stuff that generated those questions. "They said, 'Oh, he's another tin-foil-hat-wearing Hollywood clown.' "I felt the only real validation I needed was just being a tax-paying American who loves my country. "I've done a lot of research - it's not just me, it's the people that have come before me, the experts, the engineers, the physicists and scientists and the scholars that raised a lot of these things. "I took a look at their research and said, 'Yeah, a lot of it doesn't add up', hence these questions. "Don't listen to me, do your own research, but I think, 'What happened to a time in this country when we had a constitutional and a God given right to be curious about things that didn't make sense?'