Not only did Walt Disney write fanfic of public domain characters, but he actually managed to turn those public domain characters into his personal property, to the extent that virtually no one else has been able to make any significant amount of money off of them since. That's unbelievably ballsy to a degree that even the author of Russet Moon couldn't hope to match. Better yet, Disney is set to extend copyright into INFINITY, so that no one else can ever benefit from the same public domain freedoms that allowed Walt to build his own empire in the first place.