The argument is based on the relationship between legal porn and prevalence of sex crimes against adults; as pornography becomes easier to access, sex crimes go down.

Also supported by the negative correlation between violent video games and real world violence.

This is also supported by the negative correlation of violent media in general and violent crimes.

While one could make the argument that because pedophiles have different brain chemistry that they would not be as affected as the general population, there’s no actual evidence of this. Additionally is the curious fact that most child sex offenders are not pedophiles, so there would be a limited reduction in actual crimes against children while allowing obscene material that could harm the general public.