The trouble with sharing information (like an ebook) is that once it's out there it's out for good. There's no such thing as 'just sharing with a friend' - if you de DRM for yourself then all well and good but if you share you can pretty much guarantee that at some point it'll end up on a torrent site - might be next week or next year - but you're just kidding yourself if you think otherwise.
This pretty much underpins the whole issue of a book as information rather than a physical object - ebook sharing makes the publishers push DRM, if you share you just make a bad situation worst for everyone. You'll be able to tell the day someone comes up with a DRM free solution that keeps the authors and publishers happy as well due to all the cheering on sites like this
