the problem isn't how us as users or Calibre as the provider look at it, it is
that publishers are extremely over cautious about the security that ensures
their books can't be used or pirated by non authorised people and without
putting this sort of protection into the app we wouldn't be able to offer their
books to listen to.
we started work on this app 2 years ago and we are still negotiating with some
publishers to give us permission for people to listen to their books on the app
that is why some books if you try to check them out will give you a message
saying you are unable to download this book at present.
this doesn't happen with the books that are calibre books but we purchase a lot
of books each year from various publishers so that our members have the most
popular recent releases to listen to and we need permission from every one of
these publishers to be able to let our members download those books.
it's not a case of your neighbour or relations would know or use your
membership details, it's more that the publishers worry that if there wasn't
any protection and people lost or had their phone stolen, or passed it on to
or sold it on to someone else and forgot to uninstall the app when they no
longer wanted for any reason without the protection whoever had the phone it's
a case of that person would have full access to their books.