Once I 'bought' an e-book that was copy protected by Adobe (my fault I didn't read the specs before buying). But because you can only read it when Adobe's servers are online no ownership is transferred to you as buyer. You buy rights to read the book on their terms.
'Hire this book' would be fair to use in this context.
(Afterwards I successfully converted to book to an e-book format that I owned with some Calibre plugins).