Earlier quoted context omitted.
Not the OP, but by good old fashioned police work, I assume non-dragnet methods, where everybody's device isn't scanned in an automated way. So instead of sifting through a massive collection of automatically collected data, taken from a vast majority of innocent people, you'd deal with explicit reports of CSAE. You'd then be able to get a warrant to obtain ISP (and other) records, cross-reference and proceed from th…
The system is basically what you describe except the explicit report is precisely what Apple send to NCMEC. By the time it gets to the police, there will be an identified crime. This has been the case for many years. I don't have the numbers to hand but I believe NCMEC receives around the order of 100 million referrals a year. EDIT: it's 20 million according to https://www.missingkids.org/ourwork/ncmecdata https://ww…
So how can this system guarantee civil freedom? How can it be guaranteed that it won't be exploited by the small number of people in power to actually inspect it and manipulate it?