Sorry about posting in this old thread.  There is an way to fix the problem but Renderosity, Daz3d, and all the other legitimate site are not willing to take that step because it will cut deeply into there profits.  The salutation is to embed a unique number in every item sold that can be associated with a customers account,  that way Renderosity, Daz3d, and all the other legitimate sites will then know exactly who is actually posting stuff illegally, and then sue them, and then ban them.