I liked this definition from UD of 9/11 truther:
A crazy person who believes the US government committed 9/11. Truthers get their inspiration from a moronic documentary called "Loose Change" which provides no facts whatsoever and has been thoroughly debunked. People who disagree with the truthers are repeatedly called government shills since truthers have no logical argument to counter the evidence.
Truther: 9/11 was an inside job!
Sane person: Prove it.
Truther: There was no plane at the Pentagon, only a missile!
Sane person: There's dozens of witnesses and plane debris was found all over the place.
Truther: ...Well the WTC was a controlled demolition!
Sane person: Why did both buildings collapse from the point of impact then? Pretty crazy the explosives were in the exact spot the plane hit and didn't explode upon impact.
Truther: ...You're just a government shill! Enjoy your FEMA camp when the NWO rolls around!
It's by a dude styling himself troofers be nuts. And guess what? Troofers do be nuts. I know a guy who is a religious Catholic, very active, and was only a little bit looney before about 2 years ago. Then he "saw the light" and now he sends me 9/11 Truther stuff from Alex Jones et al at least twice a week. I'm on his list; he sends this stuff to everyone with a BCC, so at least it's semi-professionally done. As a bonus, I also get the standard fear mongering about H1N1... don't ask. The few times I've responded I get an all caps response back about how I should be asking the Lord to open my eyes to the truth and other meaningless platitudes worthy of question beggars.
To make his emails even easier for me to discount, he uses 20 point Calibri font on all his emails as a baseline. Recently he has obviously desired to urgently increase the urgency of his urgent message, so he has cranked it up to 24 point URGENT CALIBRI BOLD. I remember thinking "Hey, here's a new phenomenon: bitmap inflation." I felt like replying to tell him that using these large fonts is sort of like the Federal Reserve devaluing our currency by the endless printing of fiat greenbacks, but as usual I chickened out. I tell myself it's out of politeness and respect. But I really think he is full-blown bonkers to be broadcasting all these inanities.
One time he included an exclamatory AMEN! inflated to 100 points of inch-high black caps. Believing my light-fingered toddlers had attacked my precious notebook again, I instinctively checked my stash of Sharpies. But momentarily I realized the pious graffito was emanating from my liquid crystal matrix, so it was only the electronic equivalent of Black Crayola on Post-it―or possibly a mixed media collage using cardboard, Elmer's glue and headline typeface incised from the Akron Beacon Journal.
I'm probably overreacting to this poor old chap—he's getting up there in years—but it's on my mind because he just sent me more links to Infowars and Prison Planet and ended with a strained segue to The Chastisement™ and a call to conversion. All of this with zero percent insincerity, I'm fairly sure. I've learned that it's no use telegraphing that I'm not interested in this stuff because I know he feels called by God to blast his message to the ends of the earth via SMTP. How would he answer the Lord on Judgement Day if he took the name of a "lost sheep" off his email list? Still the conspiracy stuff just makes my head itch and I can't help reacting to some degree.