Yes, thanks for reminding this essay. I think though that de-duplication is a lawyer oriented smoke-screen. It is based on a complete misunderstanding of Colour because Colour tracking happens at the wrong abstraction level. Colour does not exist in the computer but it is a property of the whole process. Therfore tracking content ownership doesn't happen at the bit-level of storing a copy or a pointer, but it is rather the consistency of the owner/content association.