The EULA states that while users retain ownership of movies they create, Activision exclusively owns "any and all content within [users'] Game Movies that was either supplied with the Program or otherwise made available to [users] by Activision or its licensors..." This means that any movie containing anything less than 100% user-created content (an impossible feat as far as I can tell) is under Activision's control.Which means that, unless you manage to strip your films of all Activision-owned content, what you can do with them is limited to what Activision will tolerate your doing. For example, you probably couldn't release them under a creative commons licence or put them in the public domain, and if you used them to say anything particularly controversial (as angry French Muslim youths are doing), you risk having your creation being pulled out from under you, because it's not really yours. In a sense, it is as if the basic words in the English language were copyrighted and had to be licensed in order to communicate.
A more reasonable approach would have been what the music software industry does, i.e., licensing the elements that come with the package (samples and loops, in the case of music software, 3D objects in the case of The Movies) for unlimited royalty-free use by the buyer and renouncing all rights to works containing them. Of course, Activision are a game software company, and assume that their punters are less savvy and/or less concerned with issues of rights. Who cares who really owns your movie, it's just a game, right?