Serious questions regarding this line of thinking:
Since your photo will not be scanned unless you turn on iCloud photos isn't turning it on the same as 'making a choice'?
How is the choice being taken away if you 100% still have the choice to not turn on iCloud photos and not have your pic scanned?
Whether the scanning is on your phone or in the cloud the result is the same: your pics won't be scanned unless you have iCloud photos turned on so what is all this fuss about?
And I'm not looking for conspiracy based answers. I would like an answer based on the available facts.
From what I've read, it appears as though Apple will neuralhash all your photos, on your device, regardless. Now, I may be mis-reading that; but Apple is giving some very mixed signals and giving conflicting information.
Now, if that's the case, it would be a VERY easy thing (if they're not already planning it) to just send those hashes to apple, whether or not you upload to iCloud. Since the law says that it's illegal to be in POSSESSION of those photos in any form, it's not a huge leap. Since the neural hashes are relatively small, you wouldn't even realize it's happening. Or just to flip a switch that says "Only upload the hash if there's a possible match". Once again, a VERY easy thing to do, once the software is in place on your phone.
The argument of "just turn off iCloud photos" is really a bad argument, although I've seen it used many times in this thread. The reality of it is, this has triggered alarms by a number of people who are much smarter than we are (lawyers, the EFF, etc.) and the very fact that Apple is pushing it out to essentially perform surveillance on every one of its users is frightening at the very least.
I'll ask my question again. Would you be comfortable with someone putting a camera in your house, with some AI on it to sense child abuse, with the PROMISE that they would never ever look at your spouse in their underwear. Would you be comfortable with that? I mean, people freak out that Alexa and Google Home is constantly listening.
The argument of "If you're not doing something illegal, you have nothing to worry about" is a very slippery slope to go down. The implementation of the "Patriot Act" should show you that our government isn't afraid to spy on its own citizens in the name of "safety".
Pearl Harbor should show you that our government isn't afraid of even killing its own citizens.
Eugenics should show you that our government doesn't care about human rights.
The end result, whether scanned on my phone or on the cloud, may be the same. One could argue that traffic cameras that automatically mail you a speeding ticket results are the same as if you were caught by a police officer with a radar gun. Except, it may not have been you driving; it may have mis-read a license plate, it may have been a justifiable reason, lots can go wrong when an "automatic" system is put in place.
And... once again... Apple is NOT law enforcement. There has been discussion already about whether this is considered a deputization of Apple to actively search for illegal content on end user devices, in which case, if they ARE considered deputized, they are in violation of the 4th amendment. And, if they're NOT deputized, then (IMHO) it's digital trespassing on my device.