Ah yes, I forgot to list the malware possibility. Thanks!
I agree that being able to redistribute exact copies is an important freedom and copyright should be like that by its very nature, but if we're going to say that it's ethically acceptable (even if not preferred) to watch a movie, read a book, or listen to a song that does not give you this freedom, I think it stands to reason that game data (levels, graphics, etc) is the same way, unless the game data is something functional like a script.
