Ray, I don't know what the official policy here is, however there is no liability to Renderosity in offering these items for sale. Under current legislation, (the Digital Millenium Copyright Act or DMCA), an entity which provides for transmission or storage of digital media can only be held liable for infringing material if, after proper notification by the copyright holder or a designated agent, they fail to "expeditiously" remove said material from public access. As to the items themselves, copyright law is not assumptive. If you or someone else suspects an item is infringing on a lawful copyright the only thing you can do is notify the creator & it is up to them to take action. This avoids the problem of bogus 3rd party complaints.