Omigoodness! Wow, I've never heard about a cat like that before. That must be so stressful!! I would say that the cat must have been traumatized at some point, or not socialized well when he was a kitten. Oh, that's really sad! I hate to say this, Cataholic, but my immediate thought is I wonder if your friend is thinking about giving away the kitty because it is so aggressive??? Do you think she would be willing to contact an animal/pet behaviorist or some other professional that could help her and Sam?