9/11 truthers are not terrorists in any way, regardless of what they have to say. Everybody is entitled to say and speak about their minds, so people who think that 9/11 was a hoax or created so that the US can invade Iraq are entitled to do so. They are normal US citizens who have every right.
Individuals who don't take the word of the federal government as law are not terrorist. The federal government are on record not knowing key facts for the 9/11 attacks. It's only fair that all information is readily made available for the puclic. There is nothing wrong with wanting all the answers.