Since the people who still read books are presumably going to be the ones best suited to rebuild society after the apocalypse (the real one, not the stupid bath salts one that's happening in Florida right now), this is a pretty bad omen. Especially when you consider how even if a book about how to use Facebook wasn't considered 'computer science,' there would still be a book about how to use Facebook, which implies that there are actually people who need a book to learn how to use Facebook. Start stocking up on canned goods and water now.