You need to realize it's a video game. There is no moral view in this. I'm just playing the game to have fun.
And YOU need to.l realise there are REAL PEOPLE with REAL FEELINGS behind those graphics. You're not playing arkanoids or pacman here (google them). What you are doing is not PvP, it's griefing. You aren't giggling because you had a cool, fair fight with a willing opponent, you are giggling because you just ganked another unwilling victim and you know you've upset them. That makes you a pretty pathetic person in my opinion.