In the past year or so, at least two commentators have made the provocative argument that we should think of art forgery as a positive contribution to the world of art.
On our reading list is "In Praise of Art Forgeries" a short Opinion Piece for the Sunday Review of the New York Times, by Blake Gopnik. The comments posted by readers are also interesting.
If you're keen, another source to look at is Jonathon Keats' book Forged: Why Fakes Are The Great Art of Our Age (which I've read and recommend). The author briefly summarizes his argument in the clip below.