There seem to be some fundamental misconceptions about porn going around here. As Neil said earlier re B7-related erotica, maybe it's just that I've never seen any of the offensive stuff, but ...
Most porn I've seen depicts perfectly ordinary sexual acts involving adults. Many of the people who consume it are women or 'ordinary' couples. I've seen plenty of material produced by marriage/relationship counsellors which *recommends* porn consumption for long-term couples.
I think some of the things that some people have cited here are due to confusion of cause and effect.
Tavia