first, any legal advice or interpretations of the law found on GFY should be immediately suspect including mine because much to my dismay I skipped my constitutional law classes (and college altogether) having said that here is my belief.
If this was a valid issue it would be damn near impossible to enforce. Also paysite get away with providing hardcore images for free on their tour by use of a warning page with legal disclaimer on the root.
We assume other sites like TGPs as an example also have a valid warning page with legal disclaimer on it which covers our content on that site.
it's pretty much what has been required since the interwebs was born and has worked and protected everyone in adult for all that time
I hope my fairly ignorant view on this has helped answer your question some
spaz