The other surprising thing about trolls is that they tend to come from very high-achieving and wealthy families. My father's an a high-ranking civil servant, my parents make $150k/year, and I was the "poor" in my troll group.
I always trolled ethically, though. No racism, no attacks on real-life non-participants except public figures who really deserved it, and no more misogyny than would be appropriate to the 18-year-old self that was the basis for one of my favorite troll personalities (ironically, named after a synonym for "thoughtful"; ok, I'm outed).
Is it really that much surprising? Trolling would fit well with the stereotype of "spoiled rich kids". No offense meant.
None taken. It's true.