Just read this entire thread...and as I have become accustomed to at the BAUT, a civil and enlightening discussion of all viewpoints.
I'm interested because in a small way I probably helped to initiate the 9-11 discussions as I asked for help from some here for a Moon Hoax discussion on the old Loose Change Forum site, which several regulars most graciously responded, which is probably how many of those who posted on 9-11 found there way here.
After some review, I think I agree with Fraser and the BA, the is nothing remotely astronomical in the 9-11 Conspiracy (unless your favorite name for them is "moonbats" ) and I have seen discussions spiral into monster threads that tend to consume other discussions (it led to the formation of a Conspiracy Therory sub-Forum at JREF). So in the balance, I concur with the actions to lock them here.
However, if you ever get lonely for a good 9-11 discussion, may I invite you to visit
http://forums.randi.org and click into the Conspiracy Forums. perhaps not quite as civil a discussion as one finds at BAUT, but a fair amount of expertise and knowledge to fight the good scientific fight.