Amazon is no saint in this regard [ <a href="http://www.wired.com/gadgetlab/2012/10/amazons-remote-wipe-of-customers-...">http://www.wired.com/gadgetlab/2012/10/amazons-remote-wipe-of-customers-...</a> ]; I would much prefer an open, interoperable book format, but, except for paper, that looks unlikely.