Imagine taking a photo or have in your gallery a photo a dear leader doesn't want to spread. Ten minutes later you heard a knocking at your door. That's what I'm most worried about, how is this not creating the infrastructure to ensnare political dissidents.
I am profoundly disappointed that almost all of the discussion is about the minutiae of the implementation, and "Hmm.. Am I ok with the minutiae of Apple's specific implementation at rollout?" And almost nobody is discussing the basic general principle of whether they want their own device to scan itself for contraband, on society's behalf.