After reading some of your concerns over copyright infringements I thought, hhmmm.....do a google search. So I did one on co2metal and here's what I got:

http://www.animegalleries.net/album/lastup/category/0/img/90

Anime Galleries dot Net - Last additions/angeldust01 Pics, Images ...
FractalsByRee-1103176803edit.JPG · co2metal-1087692819edit.JPG · angeldust01.jpg ·
193hd.jpg · 78.jpg. Rate this picture (No vote yet). Rubbish · Poor ...
www.animegalleries.net/album/lastup/category/0/img/90 - 63k - Cached - Similar pages

And:
http://amdwallpapers.lunarpages.com/gallery/thumbnails.php?album=5

AMDwallpapers.com Galleries - Wallpapers
co2metal-1086411211.jpg · Dreamer.jpg dreamer. 3d_fiction_2.jpg · 3d_fiction_9.jpg ·
254w.jpg Aqua Tux. a1b~0.jpg spill1 comments. something blue.jpg ...
amdwallpapers.lunarpages.com/ gallery/thumbnails.php?album=5 - 24k - Cached - Similar pages

I was also wondering if it would be possible to check IP's of offenders and ban or block them from this site?