Google researchers show how it is possible to remove watermarks on stock photos on a massive scale, automatically, and without any user intervention. But they also propose a way to defend against it.
▻https://www.youtube.com/watch?v=02Ywt87OpS4
▻https://watermark-cvpr17.github.io
▻https://research.googleblog.com/2017/08/making-visible-watermarks-more-effective.html