Without the changes they made to Stable Diffusion, it was already able to generate CP. That's why they restricted it from doing so. It did not have child pornography in the training set, but it did have plenty of normal adult nudity, adult pornography, and plenty of fully clothed children, and was able to extrapolate.

Anyway, one obvious application: FBI could run a darknet honeypot site selling AI-generated child porn. Eliminate the actual problem without endangering children.