[Dylan16807]

Getting a DMCA for one user's copy of a file doesn't mean every other user's copy is violating copyright. And that's not a theoretical concern, I remember a recent tweet about google drive having false positives in that exact way.

[joshcryer]

That's an interesting argument but the hash for an "infringing file" would be universal across all copies of said file, since presumably the DMCA striker would be claiming the file as infringing. I doubt a jury would buy it.

[Dylan16807]

They can claim that a file is infringing everywhere it exists but they'd often be wrong and I don't think inherently infringing files are a valid way to interpret copyright.

"Better safe than sorry" is certainly, uh, safer. But I don't know if you can really say the DMCA requires it.