To assume CP is reviewed manually is simply wrong. You don't want to put such weight on an individual. You want to automate it as much as possible, with as litt

To assume CP is reviewed manually is simply wrong. You don't want to put such weight on an individual. You want to automate it as much as possible, with as little false positives (and false negatives) as possible. For example, in case of a wallpaper, let's say its the Windows XP wallpaper. There's no human skin color in it at all, so you can easily be reasonably sure it isn't CP. You would not need an advanced ML for such. And they can have multiple checksums, just like a tarball or package or whatever can have an CRC32, MD5, and SHA512. Just because one of these matches, doesn't mean the other don't. Only problem is keeping these DBs of hashes secret. But that could very well be a reason the scanning isn't done locally.