Xbox have a reputation for watermarking things to a large extent to deter leakers. The first ever footage of Halo 4 Multiplayer came courtesy of someone recording it from a terrible camera, played on a CRT television, from a VHS recording, while in a barn. I would link it but it also has obnoxiously loud music playing over the top of it but if you search 'halo 4 barn leak' you will be able to find it. Admittedly I'm sure whoever leaked that went a bit too far for comedic effect