All it takes (aside from the stupid left turn that started the "Man Down!" thread) is a tap on the brakes, a slight tug of the steering wheel, a patch of oil or someone in front to forget trucks need longer distances for signals and you're wrapped against the bumper.

You're only going to hurt yourself so if you want to go for it, by all means. It's just not worth the risk for me. I sure don't understand anyone who does it while, at the same time, endorses safe riding techniques.

(I'd avoid head injuries by riding bare headed and by staying away from this practice than wearing a helmet and doing it!)