I was looking up something else and stumbled on this familiar passage from 1984, which describes perfectly the reaction of people when they encounter clear and persuasive evidence that the major events of our time, such as the assassinations, 9/11 and Boston are not at all what we are told to believe they are:
The first and simplest stage in the discipline, which can be taught even to the young children, is called, in Newspeak, crimestop. Crimestop means the faculty of stopping short, as though by instinct, at the threshold of any dangerous thought. It includes the power of not grasping analogies, of failing to perceive logical errors, of misunderstanding the simplest of arguments if the are inimical to Ingsoc [English Socialism], and of being bored or repelled by any train of thought which is capable of leading in a heretical direction. Crimestop, in short, means protective stupidity. But stupidity is not enough. On the contrary, orthodoxy in the full sense demands control over one’s own mental processes as complete as that of a contortionist over his body.