THe argument against porn RE: violence is that it objectifies women as sexual objects - i.e. rather than as human beings - and as such makes the potential attackers (who would, after all, be somewhat deficient anyways) more likely to attack without regarding their victim as a fully fledged human. Perticularly with regard to rape.
Personally, I think any link would be minimal at best - basically if you;re dealing with people of the mental calibre that they are influenced to this degree by porn or any other media, then you;d be better off finding these people and stopping them, rather than scapegoating one of the seedier sides of our media.
(oh, you realise consume doesn't mean 'eat', don't you?)
