This is effectively a virus scanner. Files are hashed (in a fancy way), compared against known hashes, and matches are reported. Your Windows desktop has Windows Defender. EFF lost a lot of credence to me after the Best Buy case. They made this big fuss about how Geek Squad employees were agents of the state for reporting CSAM on a customers hard drive, while doing a requested file recovery. When searched, the defend…
The analogy isn't great. Anti-virus/malware software provides a benefit to the owner of the device; Apple's software does not.