I also like the "airgap" benefits of books vs proprietary readers, nobody can log into a book and ninja edit for future political reasons or delete them for copyright reasons.
Personally, I'm not this paranoid. I buy the books on my kindle and copy them into Calibre and strip the DRM. I get all the benefits of having an permanent archive and being able to enjoy modern technology.
For now we can strip DRM, what if all near future readers have a TPM-like hardware key that can't be copied or sniffed that must be present to decrypt the text.
Probably the most terrifying "feature". I agree wholeheartedly. Its kinda scary how technology, if universally adopted, could be a past censors dream come true.