"Sex offender", in a legal context, usually covers a lot of ground, depending upon the jurisdiction. I can include everything from rapists to a guy who flashes himself at little old ladies. It also often includes "statutory rape", which, in some jurisdictions, is very messed-up in how it's structured. And, of course, it includes offending pedophiles.Also, I think it's really unfair that this discussion is generally conflating the terms "sex offender" and "pedophile."
There are definitely different degrees of offence.
In which case, their desires remain in the world of thought and fantasy -- which are not punishable by law, nor do they pose a threat to society. People fantasize all kinds of nastiness -- take horror/slasher movies, for example. ;) As long as it stays in the realm of the conceptual, there's no crime.there are non-offending pedophiles in the world. Lots of them.
Just to be clear, collecting and/or purchasing photos involving child pornography is a crime, because it enables and supports an industry that exists based on sex crimes against children. Artwork, which is not based on real children, is not a crime, however. Otherwise a lot of dudes in Japan would be in big trouble. :)