Why are people so easily manipulated by the media?

I have noticed that, even in this day and age, people are so easily brainwashed by the media, religions and politics. For example: Second hand smoke is bad for you when no study has ever been conducted to prove it... Or school shootings, let's put bars on windows and lock the kids in ... Or all pedophiles are child molesters (which is like saying that all Christians are murderers, if one does it then they all must do it) ... Or saying that terrorists have not won and yet, they have. (Have you been to an airport lately?) It just seems like if the papers print it, or reporters report it then everyone believes it when we all know, 90 percent of it is nothing but sensationalism... Why do you people always believe what you read?