> ... there ARE going to be false positives that apple records some database. Millions of iphone users are going to have a non-zero "possible childporn" score.

> ... there ARE going to be false positives that apple records some database. Millions of iphone users are going to have a non-zero "possible childporn" score. I don't think this is right. The apple pdf on the features says > With the initial match threshold chosen as described above, iCloud Photos servers learn nothing about any of the user's photos unless that user's iCloud Photos account exceeded the match threshold. This implies to me that they are using some sort of encryption to prevent iCloud from learning even how many matches there are until the threshold is met.