I have two experiences that really broke my heart.
1. There was a time when I was logging on my NatureClan character and standing there all day, everyday waiting for people to log on. When I had joined NC, it was bursting this RP helped me a lot and I've met a lot of friends through it. Now it's a small and fairly inactive group.
2. Me and my friends had decided to confront a certain RP group that made fun out of serious subjects (rape, cancer, ect.)
They yelled at us and laughed at us, saying that their friends who had lived through these things didn't care about them making fun of it. Well, turned out that I was very sensible to one of the subjects. I broke down crying (which trust me, doesn't happen to me a lot) and didn't log on my main account for months fearing that the group would recognize me.
Fortunately, the group we confronted went inactive and I never saw any of the users again. ;v;