Comment by crooked-v

The hashes involved in stuff like this, as with copyright auto-matching, are perceptual hashes (https://en.wikipedia.org/wiki/Perceptual_hashing), not cryptographic hashes. False matches are common enough that perceptual hashing attacks are already a thing in use to manipulate search engine results (see the example in random paper on the subject https://gangw.cs.illinois.edu/PHashing.pdf).