A person who makes boasts and bullies people only because he/she knows the anonymity of the internet means they can't actually be found and challenged to a real fist fight. Generally the highest form of cowards, pretty common now though.
Yea, that guy said a lot of hateful shit, but that's only cuz he was Internet strong. Bet he's never called a black guy a nigger to his face once, no matter how many times he typed it tonight.