In theory, since a movie is just a series of still frames, the same techniques could be used to modify individual frames as are used to "photoshop" a still image, (albeit, tediously). You might find the tools and tutorials at this site of some help in analyzing individual frames: http://fotoforensics.com/
You might also find some of the information at the associated Hacker Factor blog of use: http://www.hackerfactor.com/blog/index.php?/categories/17-FotoForensics
With this logic applied, beleaguered industries worldwide can gain instant relief! Just think, of it. For an example, when you fill the tank or change the oil of your car, you'll owe the manufacturer for your *new* vehicle!
Remind me again how Circuit Court judges are selected.
"Experience has proved that some people indeed know everything." -- Russell Baker