How can you be so sure they're not simply aficianados who like to trade their wares? Ask any cop who works on kiddie porn cases. Nearly all of it is freely traded by aficianados.
39,000, non-profit, animal sex websites..
?
(Thirty Nine Thousand... )
There are over 39,000 barnyard sex sites linked at Google. Start clicking and tell me there aren't a ton of for-profit sites.