Quote - > Quote - I don't think that downloading an image from the internet amounts to a copyright infringement, even if the site, from which the download takes place, claims that it does.

Want to bet on that ?
Downloading images from any site, be it Renderosity or the owners own website, is breaching the image owners copyright - the fact that it happens doesn't make it legal.

 
This part I don't understand.
Any time I look at an image here, it is downloaded to my cache.
After a while I have hundreds of full size images in there and have to clean them out.
So how does that breach copyright?