Except that demand destruction increases demand for substitutes, and one of the substitutes for viewing the existing child porn is abusing children to make more. There's another theory that watching child porn is a thoughtcrime that makes pedophiles more rather than less likely to go abuse children, but we've seen just the opposite with adults—rape and sexual assault stats decline as legal, adult porn becomes more prevalent. The whole mess reeks of the politician's fallacy (we must do something! this is something!) with little regard for the actual consequences, especially when they've started prosecuting teenagers over pictures of themselves.