Technically, you're probably right. I don't care. Companies can (and do) weasel their way into anything by saying it was part of the license agreement you signed. Fair use is fair use in my opinion. Buying the physical copy gives me the real thing, forever. Buying the digital copy for basically the same price shouldn't take my rights away based on a license.

Don't even get me started on Amazon's new Kindle format that's literally and strictly a simple PDF wrapped in encryption. I bought one of them for a class expecting to read it on my Touchpad, but apparently it only works on Mac/PC/iPad and nothing else. Complete bullshit. This is why people break DRM.

Under the first sale doctrine, he has a right to do whatever he wants to the bytes that he has purchased. The underlying content (i.e., the "book"), however, remains subject to stuff like copyright, etc.

But in all seriousness, the DMCA does authorize DRM-cracking if necessary to allow the customer to enjoy the full private use of media they have purchased