When in history has censorship been the right thing to do?
Censorship has always been a tool used by those in power to suppress the opinions and rights of those they controlled. Censorship has always been a tool used to manipulate those they controlled. If, as an individual, group, organization or authority, your policies benefit the masses, why would you need to suppress free speech? If a majority of your followers are benefitting from your actions, why would complaints from a minority (that don't apply to the majority) even be considered threatening to your position or status?
So, again I ask, when in history has censorship been the right thing to do?