This clip of Downfall has been remixed loads of times and this time the EFF have had a go talking about the fair use rights that allow people to remix this clip. It's very meta I guess

here's the story behind it and the trouble they went to to make sure it was fair use to make the point that this sort of thing that should be legal and sort of is but with so many caveats it's hard to deal with
http://www.eff.org/deeplinks/2009/05/when-fair-use-fairly
http://ideas.4brad.com/hitler-tries-dmca-takedown