We get a lot of complaints, and we have never taken down content due to a copyright complaint. In order to do this we have to use hosts which are less bothered about such issues. However, they are of course still very bothered about **********. Regardless of if you agree with it or not, this type of art would be considered ********** in most western and European countries (ie, anywhere there is a decent datacenter).
If we're to keep the site safe, stable and online we need to try and draw a line somewhere, keeping our hosting providers happy and avoiding the attention of international agencies. Otherwise, we'd be constantly hopping hosts every time we get a DMCA or ********** complaint.
We decided to try and draw the line at "realistic/semi realistic depictions of prepubescent characters", this doesn't mean <18, it means pre-puberty/preteen. Realistic/semi realistic tries to allow stylised characters such as Nergal's games, whilst disallowing content from creators such as "Mysterful Games". Obviously there are grey areas but unfortunately this is unavoidable.