This may sound bad, but I'm an avenger.
When a person does something wrong, no matter who they are, they should have to pay for it. When someone really wrongs me, I hold that desire for vengeance for a long time. It is my strong view that when someone does something to hurt someone else, they should be punished accordingly. And if they aren't, then I take it into my own hands.
But then it also depends on what they have done and how serious it is. I'm not gonna seek revenge for something stupid. But something seriously wrong, oh yeah. I'll seek revenge for that.