Movie Maker in-game is more of the newest way to advertise for groups and/or look for mates, keep that in mind. As far as I know however, the Movie Maker itself does not publish to any websites such as YouTube, as Hakumi kindly stated above; you'll need your own screen recorder and video editor. Sadly the Movie Maker that you see on the main menu (where you login with your username and password to access the character selection menu) is not available, and probably never will.