Having,
for whatever reason, spent a
good deal of time in my late
childhood around a few special
morons who actually committed this
act on more than one occasion - I'd have to say I've
never heard of anyone actually
dying from being curbed.
Horribly disfigured with a broken jaw that never sets right and dentures for the rest of their life - yes. Death, no.
...And don't look at me like I'm encouraging this sort of activity, nothing could be further from the truth. The only half-thankful element to all of this is the only way you're ever going to be able to curb someone is if they're already unconscious - so they at least don't get to experience it first hand.
Shudder