That's the point: catching the bad guy foolish enough to keep
known CSAM images on their phone, while not technically invading the privacy of any good guys. Anyway, if apple wanted to
covertly invade their users' privacy, they'd have no technical problems to do so.
What it takes to accept is the "nothing to hide" mentality: your files are safe to scan (locally) because they can't be known CSAM files. You have to trust the scanner. You allow the scanner to touch your sensitive files because you're not the bad guy, and you want the bad guy be caught (or at least forced off the platform).
And this is, to my mind, the part Apple wasn't very successful at communicating. The whole thing should have started with an educational campaign well ahead of time. The privacy advantage should have been explained again and again: "unlike every other vendor, we won't siphon your files unecrypted for checking; we do everything locally and are unable to compromise your sensitive bits". Getting one's files scanned should have become a badge of honor among the users.
But, for some reason, they tried to do it in a low-key and somehow hasty manner.
What it takes to accept is the "nothing to hide" mentality: your files are safe to scan (locally) because they can't be known CSAM files. You have to trust the scanner. You allow the scanner to touch your sensitive files because you're not the bad guy, and you want the bad guy be caught (or at least forced off the platform).
And this is, to my mind, the part Apple wasn't very successful at communicating. The whole thing should have started with an educational campaign well ahead of time. The privacy advantage should have been explained again and again: "unlike every other vendor, we won't siphon your files unecrypted for checking; we do everything locally and are unable to compromise your sensitive bits". Getting one's files scanned should have become a badge of honor among the users.
But, for some reason, they tried to do it in a low-key and somehow hasty manner.