If you can control perception, then you can control behaviour. If you can dominate the narrative so people are only hearing one side of the story or one version of the story then you are going to dictate the perceptions of vast numbers of people, especially if they haven’t had any other angle to consider. This is so easy when you are addressing a population who do not question anything:


Q: How do you know that? 

A: I saw it on the news

Q: How did they know that?