If you're abusive; swearing, harrassing, bullying other users... If 당신 use offensive content; offensive 코멘트 (I guess) 또는 if 당신 spam; 당신 give someone an unnecessary number of props.
I'm not really sure, bot those are my best guesses :)
If you're worried, I'll warn 당신 about these three known abuses that can be done on Fanpop.