we need to be more vigilant and MERCILESSLY FLAG those violators! Of course one has to make sure about it because it could be that for example someone rips off your art from elsewhere on the net and posts on Steemit, and some time later, you post it yourself (and then you might get flagged by an over-eager user) - so doing an image search and checking who the artist really is must be done.
A few times I had posted my essays that I had published previously (with links and all) and @cheetah caught it. Just wondering if that kitty can detect images as well?
I recommend https://tineye.com/ - I used them before and found some of my art being ripped off and used commercially!