He shrugs off such unfortunate transactions as part of doing business.
Although he didn't enter the business for political reasons, Thompson has become passionate about gun rights; his website offers a discounted membership rate in the National Rifle Assn. He's taken up sport shooting as a hobby. And he expresses deep respect for the gun enthusiasts -- cops, hunters, sportsmen, collectors -- who shop at his sites.
Few try to scam him with credit card fraud. Many who call his toll-free line end up chatting with his employees as though they were old hunting buddies. They're good folks, Thompson says, "one of the pleasures of being in this industry."
One of those customers, Nicholas Koch, strolls into the showroom on a cold afternoon looking to add to his collection of Glocks. A former Marine, he has six or seven handguns at home -- he's lost count -- and two rifles. He settles quickly on a sleek 9 mm.
"I like firearms in general," says Koch, 24. "And these look sexy, for a pistol."
He fills out the required form, checking "no" to such questions as: "Are you a fugitive from justice?" and "Are you an unlawful user of, or addicted to, marijuana . . . or any other controlled substance?"
A clerk calls Koch's name and Social Security number into a federal hotline and gets the all-clear. "Can I get frequent Glock miles?" Koch jokes. "You guys should make punch cards. Every time you buy a gun, you punch out G-L-O-C-K, and when you're done, you get a free T-shirt."
Koch, who's studying for a college degree in geology, resents the critics who fault Thompson for the crimes his customers commit. "It's like Chevy getting blamed for people driving drunk," he says.
Thompson appreciates the support. In recent weeks, he's received hundreds of nasty e-mails:
"You make me sick."
"You've got blood on your hands."
"I sincerely hope you go to hell for what you've allowed happen!"
"HOPEFULLY YOU OR SOMEONE YOU KNOW WILL MEET THE SAME FATE AS THE WONDERFUL YOUNG KIDS AT THOSE 2 COLLEGES."
In Thompson's experience, then, it's the anti-gun crowd that spouts violence. After Virginia Tech, vandals splattered his store with eggs. Some of the e-mails threaten his children.
Gun owners, by contrast, seem rational and responsible -- and that's why he wants to see more of them in classrooms.
"I'm not going to say that we don't have a problem with violent crime in America," he says. "But there's a logical answer."
Thompson starts with the uncontested fact that campus shootings are often over before law enforcement can respond. At Virginia Tech, Cho barricaded the classroom building and shot himself in the head as police broke through. At Northern Illinois, Kazmierczak killed five students in less than two minutes; he committed suicide before police arrived.
But what if someone else in those classrooms -- a student, a teacher -- had been carrying a gun? Isn't it at least possible some lives could have been saved? Isn't it worth giving our children that chance?