#DRM really suck in so many ways! Not only can it prevent you from reading an #ebook on other apps than the one decided by the bookseller, but it is sometimes not even compatible with other widely used DRM system, like #Kindle or #Kobo. This means that if you have a wide panel of readings, especially academic works, you'll have to buy multiple #ereaders and load your books in multiple #readingapps. This makes it nearly impossible to maintain a coherent library, even with #calibre .