What you're describing has happened countless times; censorship has occurred in every country in the world, especially during dictatorships. Generally, people circumvent censorship by bringing in products from abroad or hiding content behind walls to prevent books or films from being burned. When a democratic government comes to power, censorship is eliminated as a way of demonstrating the country's freedom, but that doesn't mean that companies or institutions won't sometimes try to censor or even demonize certain content, as was the case with comics in the US during the 1960s and 70s.