This is obviously sarcasm but I'd preface it with an explanation since HN is multicultural and not not everyone here is brought up to catch it effortlessly.

Edit: The point here is that even if Apple tries very hard to make this be only about photos about to be uploaded to the cloud, if the percentage of phones that turns off iCloud storage increases as a response to this new "snitch-on-me" feature that will be a very good argument for law enforcement to ask for a list of IMEIs that are not using iCloud, and it will also tempt them to demand that Apple start scanning all files.

You own your iPhone. Apple owns iCloud servers.

It's very simple. You want to upload images to iCloud? Then let your phone scan it and upload it. You don't want your images scanned? Don't upload them to iCloud.

As skinkestek kindly pointed out, the point of my sarcastic comment was that now that the precedent of scanning the contents of users’ devices - as opposed to the contents of Apple’s servers - has been set, deciding whether to do so based on the state of a single “Store photos in iCloud?” toggle is going to start looking awfully arbitrary.