> "I've read a few of Cooper's books and the short answer is yes, pedophilia is a common theme in his writing (as is incest and necrophilia)."
Because of the words 'book' and 'writing', I have the impression that everything there is written text and no certainly no pictures.
This puts it in a nebulous position, at least in the USA.
Dunlop v. U.S., 165 U.S. 486 (1897), ended up ruling that text-only content can be deemed obscene and being text-only is not a reason to get total 1st amendment protection. However later cases, decided there was a division between erotica and obscene material, which is essentially decided on a case-by-case basis subjectively.
When it comes to things such as obscenity, its not really enough to go by our 'feelings' and intuition on the matter.
For instance, would you believe the US is a fully functioning, 1st world democracy, where sex toys are illegal (Alabama, upheld by State Supreme court and enforced as recently as 2009)?
To me, personally, anything that comes entirely from someones fanciful imagination, no matter how distasteful, should not be considered illegal unless it directly results in the harm of another individual.