The reason they care now is because they have been trying to increase privacy and encryption of their services, and the powerful political flag that gets waved

The reason they care now is because they have been trying to increase privacy and encryption of their services, and the powerful political flag that gets waved in opposition is CSAM. (second place is Terrorism but that engenders more political debate) Even if the real government motives for wanting decryption backdoors or no encryption at all are less pure in motivation, CSAM investigation and prosecution is something that nobody wants to argue against politically. That's the only explanation, sinister or benevolent, that makes sense to me for why Apple wanted to do this with all of the rube goldberg steps they created to make it inconvenient as a direct surveillance tool. . Given the priors that they want to avoid decrypted dragnet scanning of user data on their servers, limit who at Apple has access to user data on their servers (even when compelled by govt warrant), and that they can't continue down their road of device and cloud privacy without addressing CSAM, this is a solution that attempts to fit those measures. I don't think that makes it a good thing. There is a clear ethical boundary for most people between "I uploaded this to your server and you scan it" versus "I'm about to upload this to your server so you run a scanner on my device, and that scan can result in a human at Apple seeing some kind of censored/thumbnail version of my personal photos." Apple tried to find a clever work around to the above assumptions but their solution is something that feels like a worse privacy violation than just scanning everything server side.