I know, and broke off friendship with, a person who was being cruel to a fellow SCA member.  She's very heavy, gained a lot of weight after her chemo, and she's asthmatic, too.  He was making really nasty remarks of how, becuase she's not able to breath, all she must do is sit around snacking all day.  She's a young woman, she has her whole life ahead of her, she didn't need that kind of abuse.  I told him where he could shove his comments and told him not to talk to me anymore and went to her to help cheer her up.  He was, needless to say, more than a little shocked to hear anyone tell him off like that.