What is the real motive behind Apple's intention to surveil all product users' image collections?

US law imposes a scanning and reporting requirement on cloud providers. You can read about it yourself. 18 USC 2258A has reporting requirements and you can find other references from there.

My guess would be that Apple legal came to the conclusion that they could not ignore this requirement and end-to-end encrypt iCloud photos without finding a way to scan for these images.

Scanning on device allows encryption of iCloud data while still meeting the requirements under federal law. If they do that, then this feature is a significant win for privacy compared to the situation we have today.

There's a lot of fake news around this feature. They are not scanning for arbitrary child pornography. They're scanning for a set of known images that all cloud providers look for.

A second, separate feature, provides parental controls for nudity sent or received through iMessage. This does not report to anyone if it is not enabled.

/r/apple Thread