They've said the on-device scanning is done only when you are using iCloud Photos. So it's on-device scanning but only when you are deciding to share your photo

They've said the on-device scanning is done only when you are using iCloud Photos. So it's on-device scanning but only when you are deciding to share your photos with Apple... At least that's how it is for now. https://www.macrumors.com/2021/08/05/apple-csam-detection-disabled-icloud-photos/ https://www.macrumors.com/2021/08/05/apple-csam-detection-di... "CSAM image scanning is not an optional feature and it happens automatically, but Apple has confirmed to MacRumors that it cannot detect known CSAM images if the iCloud Photos feature is turned off."