Dropbox DMCA takedown in personal folders (twitter.com)

And after looking through a good portion of the thread it appears that the story is: 1) He was storing copyrighted material 2) When you create a share link for a file it checks its hash against a blacklist provided by copyright holders 3) The check failed and he received a message that he couldn't share the file do to a take down request, assumedly on someone else's link to the same content.

Don't really think there is much to see here except people getting worked up over a poorly communicated situation.