So a guy watches an unfamiliar giant football black male act suspiciously in a neighborhood with a huge robbery rate.
The guy questions Trayvon Martin.  No physical contact, just words.  Yaba yaba.  You never have to talk to anyone, just provide a DL if you're driving.  We are citizens not livestock.
Trayvon Martin attacks George Zimmerman.  Initiates force.  Starts violence.  Attempts a lethal blow to the face, etc.
George Zimmerman defends himself with whatever is handy.
Now Trayvon Martin is a golden saint; never mind his problems at school, broken family, towering football figure.  F that.  George Zimmerman is a hero, like Bernie Goetz.
Initiators of force are subject to evolution.
Also works for nations, hows that Occupy Iraq and Invade Afghanistan working out for ya? 
Say what you want; touch me and you die.  Its simple.
Impulsive, violent "children" learn that assault is 
not a joke.  
Buy ammo now, for the riots when GZ is exonerated.