In 2004, film critic Roger Ebert "realized that auteurs weren't the only ones who had things to say about movies, and suggested that experts in other fields or even just fans of the movies could create MP3 commentary tracks to discuss their favorite films, which could then be downloaded and played alongside them." This inspired Slashdot reader #14,247 to produce his own commentary on Hayao Miyazaki's first movie, Lupin III: Castle of Cagliostro
-- and 13 years later, to release a new commentary track celebrating the film's 35th anniversary. Robotech_Master
Among other things, it offers proof that excessive copyright really harms creativity by restricting the uses people are able to make of prior art -- by showing what can happen when people get away with ignoring copyright and creating anyway. Not only were Lupin III and Cagliostro effectively inspired as "fanfic" of characters and works that had come before, many of those characters and works were effectively fanfic themselves -- and Cagliostro in turn inspired parts of a number of other works that came afterward, including a couple by Disney.
Anyone else have a favorite example of a movie that bends the rules of copyright law?