Fiona:
I've also seen some (admittedly only a few, *but*) fan porn stories which I would say excuse, or even romanticise, rape. Which as a woman, if not a feminist, I find somewhat disturbing. You can argue that this is only the extreme fringe-- but I think this is the fan porn equivalent of the "genuinely nasty stuff" you referred to, Neil, and it's worrying.
You could also say that it's *fiction*. And rape fantasies are supposed to be rather common.
Tavia