Apple already scans your photos for faces and syncs found faces through iCloud. I’d imagine updating that machine learning model is at least as straightforward as this one.
The only difference is intent. The technical risk has not changed at all.
And not just Apple. Once technical feasibility is proven, I can easily see governments mandating this scheme for all devices sold. At that point, it can get even more ugly, since e.g. custom ROMs and such could be seen as a loophole, and cracked down upon.
I will also note that, while it may be a hypothetical in this particular instance as yet, EU already went from passing a law that allows companies to do something similar voluntarily (previously, they'd be running afoul of privacy regulations), to a proposed bill making it mandatory - in less than a year's time. I don't see why US would be any different in that regard.
At this point of the discussion, people usually pivot to scope creep: the on-device scanning could scan all your device data, instead of just the data you put on the cloud. This claim assumes that legislators are too dumb to connect the fact that if their phone can search for dogs with “on-device processing,” then it could also search for contraband. I doubt it. And even if they are, the national security apparatus will surely discover this argument for them, aided by the Andurils and NSOs of the world.
As I have repeatedly said: the reaction to this announcement sounds more like a collective reckoning of where we are as humans and not any particular new risk introduced by Apple. In the Apple vs. FBI letter, Tim urged us to have a discussion about encryption, when we want it, why we want it, and to what extent we should protect it. Instead, we elected Trump.
The precedent now established by Apple is that it's okay to scan things that are physically in possession of the user. Furthermore, they claim that they can do it without actually violating privacy (which is false, given that there's a manual verification step).
Apple’s claim, further, is that this approach is more privacy-preserving than one which requires your cloud provider to run undisclosed algorithms on your plaintext photo library. They don’t say this is not “violating privacy,” nor would that be a well-defined claim without a lot of additional nuance.
Instead, a forum of presumably technically savvy people are reduced to hysterics over implausible futures and a letter to ask Apple to roll back a change that is barely different from, and arguably better than, the status quo.
We need both - develop free software alternatives (which means to stop pretending the alternatives are good enough), and to get real about supporting legal and governance principles that would protect against abuses.
If people want to do something about this, these are the only protections.
icloud scans for those faces
finds those faces and ties them to other ID accounts via face - then via fingerprint recognition to a device, and to a location based on IMEI etc.
Apple's platform is literally the foundation for the most dystopian digital tool-set in history...
Once the government is able to crack the apple war chest, everything is fucked.
The "one in trillion" chance of false positives is Apple's invention. They haven't scanned trillions of photos and it's a guess. And you need multiple false positives, yet no one says how many, so it could be a low number. Either way, even with how small the chance of it being wrong is, the consequences for the individual are catastrophic. No one sane should accept that kind of risk/reward ratio.
"Oh, and one more thing, and we think you'll love it. You can back up your entire camera roll for just $10 a month and a really infinitesimally minuscule chance that you and your family will be completely disgraced in the public eye, and you'll get raped and murdered in prison for nothing."
So iCloud Photos circa 2020 [and Google Photos and Facebook and Dropbox and OneDrive] aren’t a risk you should be willing to take.
This feature doesn’t change anything in that regard; the scanning was already happening.
Apple's new policy is: "of course your phone is scanning and flagging your private files to our server - that's normal behavior! Don't worry about it".