I don't think it's somewhere I would visit either, any other shop would simply put a label on the cover or simply not sell the item at all.

I also despise censorship, it implies that we are too stupid to think for ourselves. Warnings are fine, but not shops banning the sale of certain products to certain ages simply because there is language some people deem bad or there's some fake blood or some sex (oddly sex is legal at 16 here yet porn is rated 18, stupid)