Everybody knows that it is easy to create an identical copy of a digital file. Within seconds you can have a duplicate of a film that is absolutely indistinguishable from the original.
This has posed some problems to artists working in digital media, as the monetary value of art was and is strongly linked to scarcity, artificial or otherwise. Often this problem is solved by adding some material aspect to the digital video. A Francis Alÿs film on his personal website is in no significant way different from its counterpart in a museum collection, but in the latter there is additional documentation or objects that are shown together with it.
This is the common solution to the problem of the creation of copies. Yet this simplicity in making a copy and distributing work comes with an interesting paradox if seen in the light of the traditional art forgery.
A forgery doesn't reproduce the image, but the object and its conditions of creation. If one forges a painting, one needs to use the right support, the right paint, the right order of brushstrokes and so forth to make it believable.
To apply this logic to a film, however, would be a nearly impossible task. You would have to reproduce the lighting, the camera angle, focal length and settings, the location and the placement of objects in it for every single second of the video. Not to mention any living beings and their exact movements.
This doesn't get much easier for films made entirely out of found footage. To locate each and every clip, together with any kind of edits that were performed on them, is simply impossible. A video does not contain any information about its origins and since its flowing in time, the amount of things that define it are compounded to near infinity.
All of this already exemplified in the short story 'Pierre Menard, autor del Quijote' by Borges, wherin creating a copy of the final product is shown to be easy, while reproducing the physical reality that led to the final product is improbably absurd.