Even for the child protection purpose alone... the 30 photos threshold thing is meaningless unless the false positive of the hash matching process becomes trans

Even for the child protection purpose alone... the 30 photos threshold thing is meaningless unless the false positive of the hash matching process becomes transparent. To achieve good recall rate, the hashing has to be in feature space instead of a plain md5 on the jpeg file (otherwise any compression or metadata change happened to the file would render the reference dataset meaningless), and I don't think anyone can promise that this has no false alarms, i.e. you take a pic of your child playing in the pool but accidentally get a hash collision. Of course this is not the point. But skimming through the article I'm not impressed by these mostly irrelevant bits either.