The legitimacy to his complaint is in B&N not warning everybody that you have to update frequently. Not having a nook I can only assume that they didn't. Or that he didn't pay attention to the notice.
Has any nook owner been warned of this possibility before?
Does B&N state that you can pickup reading your ebook on your nook, computer, or cell phone? If so he might have thought that they kept track of all the books on his nook. Naive, but possible.
On the other hand, abookreader, is right, the world would come to an end if B&N did that.