Assuming they are hashing the images or videos and only comparing the hash in practice, why doesn't Facebook implement a client side JS method for the hash gene

Assuming they are hashing the images or videos and only comparing the hash in practice, why doesn't Facebook implement a client side JS method for the hash generation. Only thing uploaded is the hash. Use standard ML Algorithms to validate if the image includes nudity and confirm the hash overlap. Also need to be hesitant since people at FB will be able to see these images (as recently mentioned in another post on HN where some random folk ended up viewing a Google Doc shared via Messenger)