“You know the very powerful and the very stupid have one thing in common. They don’t alter their views to fit the facts. They alter the facts to fit the views. Which can be uncomfortable if you happen to be one of the facts that needs altering.”
Or at least so says the Doctor in the Doctor Who episode, “The Face of Evil,” originally airing in 1977.
One way “changing the facts” happens is by banning or altering books. In China, among other things, definitions in dictionaries that contradict the Chinese government’s worldview, for example that Taiwan doesn’t exist as a separate country, has led to them defacing dictionaries by tearing or pages or covering with stickers. And it isn’t only China. India insists on all imported texts that mention Kashmir, even magazines, have content saying the Kashmir region is contested between India, Pakistan, and China instead of 100% Indian will be defaced to remove or cover up the maps.
Banning means you can’t get a copy to decide for yourself.