[KaiserPro]

just think about the sheer number of people that report stuff.

given that facebook has less than 1k moderators, do you honestly think that they'd just let the moderators sift through everything manually?

obviously you'd classify stuff first, checking against known images is easy. Classifying new images is a lot harder, plus the ethics of training and labelling a dataset for accurate detection is pretty hard, also almost impossible to do legally.

I suspect the next best thing is detecting nudity and age of the subject, and taking the hit that you're going to prioritise a lot of malicious reports, rather than genuine.