It can't. No actions are taken on hashes alone. The procedure is, if an account uploads some number of images with matching hashes, those images are verified by a human.
This can attack that system itself, though, by overloading those humans with too much work looking at random noise, but that requires quite a large organised effort. It also requires getting a hold of actual blacklisted hashes, which I doubt anyone has, unless they have actual child pornography.
This can attack that system itself, though, by overloading those humans with too much work looking at random noise, but that requires quite a large organised effort. It also requires getting a hold of actual blacklisted hashes, which I doubt anyone has, unless they have actual child pornography.