People who try to pick a fight or intimidate people, like people with balls would do in real life, except that those lamers are hiding behind their monitor, knowing that they can live out their fantasy of being a tyrant through the absolute safety and anonymity the internet offers them.
This guy in chat was trying to tell me that he was going to whip my ass - damned net-Nazi.
Used by eris in Greek Mythology to wreak havoc on people. The golden apple of discord was stolen from a tree belonging to Hera (Zeus's wife and goddess of marriage).
(This was linked by someone and I thought I'd provide and explanation).