While probably more along the lines of DisproportionateRetribution,
this troper was once picked on a bit by one guy on the hockey team, and picked on a bit worse by the people said guy from the hockey team associated with. One day, when said guy got into a spleen-rupturing accident on the hockey rink, he ended up hospitalized for a while, and when said guy came back I said "I'd frankly have been happier if you died in the hospital" to him. I didn't quite mean it, and I later apologized, but the point is that the reason I said it to him was because it was something I thought he deserved to hear. (EDIT: For what it's worth, we were both in middle school at at time.)