Calibre (unsupported) plugins let you remove DRM from Kindle books, so you actually can save a local copy not connected to Amazon in any way. I keep buying Kindle books while this is still possible, and will stop if it ceases to be.
be careful with sharing books you got with this method. The Calibre plugin does remove the DRM but not the Amazon User ID they embed inside. Keeping it for you is fine, otherwise you need to be more cautious.
I don't share books, I just store them in epub format so that I can read them in Marvin. But thanks for the heads up. Do you know if the Kindle user Id is saved in the epub file when converted with Calibre?
Is there currently a single source of truth for the content of books and other written media? Something like a hash of all the contents that can be stored in some indelible way (blockchain maybe?) so that as time passes people can verify that the content has remained the same?
