User blog comment:Plexioth- xD/Monster Hunter 3 Ultimate/@comment-248687-20120421042130/@comment-1653324-20120421042740

The first explanation I read way back for region-locking, is that it was an important aspect of DVDs. It prevented piracy from spreading. If an earlier release of a movie in one region was successfully pirated, it wouldn't spread to other regions, and the creators can find a way to resolve the exploit in the newer releases of the movie in other regions. But Nintendo games are already so hard to pirate.