Outlawed by Amazon DRM:

This is becoming my hobby horse, but it bears repeating: this is the real “walled garden” effect we need to worry about. What I need to have and keep open are my data formats. I don’t need the source code for the applications that I run; I don’t need warm fuzzies from the thought that I can swap out my operating system for Ubuntu “Rabid Ratel.” Those are ways that those of sufficient nerd studliness can keep their data open, but for 99% of humanity they’re not practical ways. Open or even de facto standards like RTF, MP3, MP4 and EPUB—when kept free from DRM—are what we need to be strongly advocating for. The music industry has mostly given up on DRM; it’s time for the publishing and video industries to follow their lead. (You’d think that merely knowing the RIAA was, in any way, more progressive than you are would be enough to shame you into action, but sadly not.) Some DRM is worse than others—Apple’s tends to be better at staying out of your way than most and, as far as I know, wouldn’t let Apple do what Amazon did here even if they wanted to—but fundamentally, you need to be able to control your own data, even if that control makes the people who sold you that data twitchy.

Source: Coyote Tracks