It's also quite hypocritical to sell a book about privacy that is encumbered with DRM.
Aren't they two different things? The open software community has been, in general, a big supporter of human rights, but every author or artist should be able to decide how he or she sells or gives away their creations. (Am I missing some important point?)
Maybe in theory, but when the DRM tracks when you're reading the book:
It depends on the DRM. If the DRM is the type that identifies and reports on the identity of the user, then it is ironic. But if the DRM is user-neutral and doesn't report back to anyone, then you are correct.