I forked a repo on GitHub. A few weeks later a DMCA take-down notice was issued against the repo (and all forks). Someone claimed the repo had stolen their copyrighted stuff.

Unfortunately, I couldn't verify whether the claim was correct because I wasn't provided with a copy of the original copyrighted material. So it wasn't possible for me to tell if the DMCA was genuine or not. I suspect the DMCA claim was valid but it was impossible for me to tell.

GitHubs process around the DMCA did not fill me with joy.