ducadveritatem
Also a good thread from Matthew Green, a privacy/cryptography wonk, on the subject: https://x.com/matthew_d_green/status/1800291897245835616?s=4...
You should look more into their security architecture if you’re curious about stuff like this. The way Secure Enclave, E2EE (including the Advanced Data Protection feature for all iCloud data), etc. The reality is that they use a huge range of privacy enhancing approaches to minimize what data has to leave your device and how it can be used. For example the biometrics you mention are never outside the Secure Enclave in the chip on your phone and nobody except you can access them unless they have your passcode. Things like running facial recognition on your photos library is handled locally on your device with no information going up to the cloud. FindMy is also architected in a fully E2E encrypted way.
You can browse their hundreds of pages of security and privacy documentation via the table of contents here to look up any specific service or functionality you want to know more about: https://support.apple.com/guide/security/welcome/web
https://www.apple.com/child-safety/pdf/Technical_Assessment_...
Also look at their full whitepaper here: https://www.apple.com/child-safety/pdf/CSAM_Detection_Techni...
My take is that performing the initial hash matching and encrypting the results in two separate layers on device prevents Apple from having meaningful knowledge of low (under the set threshold for being flagged) quantities of matches on a user account. This protects the use of the threshold as a way to further reduce false positives. For example they couldn't comply with a subpoena that said "Hey, we know you set a threshold of only flagging + reporting accounts with 50 image matches, but we want to see a list of all accounts with 10 or more matches because we think that's good enough."
This method lets them set and enforce a threshold to maintain their target false positive rate which they say is ~1 in 1 trillion accounts incorrectly flagged.
Disclaimer: I'm not a cryptographer and could be misunderstanding this.
Full whitepaper: https://www.apple.com/child-safety/pdf/CSAM_Detection_Techni...
If an account uploads multiple images that match to known exploitative images and exceeds a threshold, then the account is flagged for review by Apple. (Note the threshold is selected to provide a ~1 in 1 trillion probability of incorrectly flagging an account.) Once they review and confirm a match, it's then forwarded to the National Center for Missing & Exploited Children for further action (and presumably referral to Law Enforcement.)
More details in their whitepaper: https://www.apple.com/child-safety/pdf/CSAM_Detection_Techni...
Except there is absolutely no evidence whatsoever that this is the case. All that is established is that if the user has explicitly opted in to the global location services option, then the device (system) does indeed periodically access location data. No one is alleging that any information is available to or shared with Apple outside of the established methods documented in the privacy policy.
There is a difference between "Apple" and "your device". If there is evidence that Apple is collecting/using location data for some purpose not detailed in their privacy policy and granular settings, then yes, that would be a problem. But that isn't what the info currently available says. It says that the system (device itself) is periodically accessing location data IF location services (globally) are turned on. Seems to me that should be expected...
If so, that sounds like a terrible idea to me. Sandboxing off applications from the hardware is a key aspect of security here. My opinion: the system should collect the location data (IF the global location services switch is on) and then parse it out following the user's granular selections for what apps they want to receive it. And that seems to be exactly the case.