I disagree with all of you. This is not being used to fight plagiarism, it is just a quick easy way for him to use a bot and make hundreds of posts, so as to up his rep.
It is totally accepted that almost everyone uses images from the web. What is asked is that we only use images that are not copyright and are free for us to use.
He did not build into his search any controls to prevent him making accusations where they are not warranted. All it does is report other copies of the same image in our posts and then makes its allegations, so that everyone else thinks that poster stole the image. It does not even check to see whether the poster has provided the source. He is going to end up attacking nearly every poster in steemit!
Exactly because it caters to the fears of people like you (people who produce their own photos), it is accepted by you, without you taking the time to think about it and see the damage he is deliberately causing hundreds of posters per day.
I am considering contacting every person he has sent his damaging comment to and suggesting they all flag his comment.