Never ever heard of one before, but i would like to see any data for injuries that were caused through one. I bet it's not as many as you might think Jerry.
I like the description of firing it at your sister, ping-pong ball leaving the muzzle at high velocity followed by a tongue of flame of up to eight feet long. Just imagine shooting at your little sister with one of these (because you just would, wouldn’t you? After all, it’s “harmless”). If the ping-pong ball didn’t get her, the flame-thrower certainly would.