It is indeed a complicated matter to produce a book and an author should probably be compensated for producing the book that they did instead of one of the other numerable but less desirable possibilities. Readers of the book could not have guessed the correct number to get the experience of reading it.
There is no obvious threshold, where writing down a number becomes different than editing a home movie or sharing a Beatles tune. You may say, "well of course this case is obvious 'cause I wrote it!" but that can't always be a good reason or you'll allow anyone to turn a number into a thought crime.
Worse still, those making the money have done their damnedest to convince us that copy-right is an immortal entity that cometh from heaven to justly enrich the sacred gate keepers of knowledge and culture. This is why there are pirates and why they are so self righteous.
It can't be helpful though to pretend that books aren't information.