FB, Google, MS, etc... already use a similar hash based system called PhotoDNA on any photos in their clouds. They reported ~20M+ instances last year, so yeah i

FB, Google, MS, etc... already use a similar hash based system called PhotoDNA on any photos in their clouds. They reported ~20M+ instances last year, so yeah it seems like the same pics do get passed around. https://en.wikipedia.org/wiki/PhotoDNA https://en.wikipedia.org/wiki/PhotoDNA