Coward With A Keyboard. Folks who would be meek in person, but find great courage in the safety of their home and behind their keyboard. Phonetically spoken like quack
99.9% of youtube trolls would be described as a CWAK
It is said of the situation where a person has the bad luck to make contact with his testicles against an undefined surface or object, intentioned or not.
Given the nature of the word, it is more appropriate to design cases where the interaction is made with a moving object, for example, a ball.
Although it is extremely painful for the victim, it tends to be considerably funny to people who witness it.
Today in the baseball game the pitcher took a nutshot; the baseball hit him in the nuts.
Man, I just watched the funniest nutshot video ever.