Linkster, I understand that Guba has been around for a long time. However, their current "sorted" interface is relatively new, but their services have been around for years.
http://www.alexa.com/data/details/tr...l=*********#top
The question comes down to the extraction process. If they give you usenet access, and you download the feeds whatnot and strip off only the iamges on your own PC, there is little or nothing illegal. When a service does that for you and resells access to the images and videos only, they have crossed a line. Stepping it up further recently, that have also started to offer transcoding and re-encoding of videos and pictures to fit IPod and PSP formats.
The most important thing at this point is that they are suddenly "down for maintenance" and I suspect they will stay that way for a while. The newest Perfect10s v. Google ruling may put a real chill on any "image reuse" sites.
Alex