So one thing I know is that for all the books by John Scalzi, their listings on Google Play Books have a note of: At the Publisher's request, this title is

So one thing I know is that for all the books by John Scalzi, their listings on Google Play Books have a note of: At the Publisher's request, this title is being sold without Digital Rights Management Software (DRM) applied. (see https://play.google.com/store/books/details/John_Scalzi_Old_Man_s_War?id=XVwOEeHTU4QC https://play.google.com/store/books/details/John_Scalzi_Old_... for an example) And indeed once you purchased his books you can download a DRM-free epub or pdf file of the book you purchased and use any tool you like to read it. I don't see similar note on the listings of his books on Kindle store, so my _guess_ would be that Amazon is unwilling do fulfill this request from the author, but I could be wrong (I never owned any kindle device anyways).