Except when it isn’t, of course.
The question of what exactly makes a book is one that has a lot of interest to those of us who publish in electronic format. The editorial team at Naked Reader Press has an approach I like (I’d like it even if they weren’t publishing me): a book is made up of the words an author writes. They don’t use DRM, they don’t lock down to a specific region, and they assume that most of their buyers are going to do the right thing and not copy the book from here to kingdom come and back.
That fits in pretty well with what I’ve noticed about people in general – there are a few who’ll do what they want regardless, and a few who’ll do what they’re told is the right thing regardless. Most of us are in between somewhere. Depending on circumstances, something we’d normally regard as wrong can seem justified.
For instance – suppose I buy a book with DRM. Not only do the restrictions make it difficult to get from my computer to my device, the seller’s software doesn’t work with my computer. In that situation, I have no moral issues with either breaking the DRM or finding and downloading a jailbroken copy. I personally think that the court decision which gave the whole DRM nonsense validity (the decision that it was illegal to break the encyrption on material you legally owned, so you could use it on hardware you legally owned) was wrong. If I bought it, I should have the right to do what I want with it, so long as I don’t redistribute it – and yes, that includes making backup copies.