It was a sarcastic comment, and I guess you are right. If the detector has a false positive rate of 0.01% that still means ~50000 false hits every day, if ever

It was a sarcastic comment, and I guess you are right. If the detector has a false positive rate of 0.01% that still means ~50000 false hits every day, if every one sends one image daily. And my guess is it's WAY more than that in volume and false positive rate.