Well, Adobe DE as a "protection" is a joke. Even non techies can get rid of it with basic google-fu, Calibre and a single plug-in. DVD CSS seems advanced compared to it.
Most "mobile device only" e-book subscription services rely on saving files to filesystem areas where users usually don't have access. Simple rooting fixes that.
But the fact that there's even attempt to remove ownership is troublesome and should be addressed on legal/political level.