Hmmm, when I was in karate we were told not to show off out of Humility and being humble. Never heard of this copyright thing. Im still kinda strange about showing people what I can do.
Arashi,
Well I learned karate formally, and ju-jitsu from a family member who was in the Army, and one reason not to show thsoe techniques off (especially the ju-jitsu) is...common sense. They are *not* sport, they're very dangerous as it was purely self-defence, mean, dirty stuff.
Off topic, but you get the point