The ultimate retaliation to any offensive action. Punching a male in the dick is many times seen as a cowardly move but depending the situation can also be used as a humiliation tactic. The phrase has been popularized by the musical group "Juicy Karkass" who actually has a song titled "Punch 'em in the dick", and is about punching people in the dick.
Juicy karkass quotes:
"...Yo look at that chump, see the way that he struts? Don't kick him in the rump, go nuts on his nuts..."
"...but you aint gotta be a dude, shit I'll dick punch a chick..."
"...fuck Sun Tzu you wanna learn the art of war? Just punch em in the dick..."