The only inhibition to me making or acquiring a copy of a book in my preferred format is copyright law, I already have a copy on paper; I can download or make a copy easily. That should be allowed as I have paid for a licence to the work (and I think is allowed under Fair Use in USA). As the copyright holder already has a digital copy the restriction of it is silly -- for the demos, who supposedly give the rights in copyright, the benefit lies in making that copy of the work available rather than forcing the extra work of having someone scan it and upload it and make it available. This later route also enables copyright infringement far more readily than the former does.