Yes, it is controversial, as the original reasoning for banning child abuse imagery was to protect the children who are harmed by its production. This is the result of a shift in thinking: while the original idea was that we should protect children, today it is a matter of morality and pedophiles are considered morally deficient. As a result, even if a pedophile has never harmed a child, the common notion is that they are a danger to the community and that we can never be too careful.
https://www.law.cornell.edu/uscode/text/18/1466A
There have been prosecutions in the past:
https://www.wired.com/2010/02/obscene-us-manga-collector-jai...
Yes, it is controversial, as the original reasoning for banning child abuse imagery was to protect the children who are harmed by its production. This is the result of a shift in thinking: while the original idea was that we should protect children, today it is a matter of morality and pedophiles are considered morally deficient. As a result, even if a pedophile has never harmed a child, the common notion is that they are a danger to the community and that we can never be too careful.