Intellectual Property

Somebody want to explain to me how an ISBN—a number assigned to a book by an outside organization, which helps to catalog the book—can be the "intellectual property" of a bookstore?

You see, I use those numbers as part of the database I have on my own books, so I don't want to be stepping on on the toes of that fine Haaarrrvaarrrd bookstore!

It wouldn't have to do anything, in reality, with (sssshhhhh!) competition and free markets would it?