Advertising-supported mass media enables people to unite in support of a common cause and rebel against tyranny. Rebellion is a coordination problem. Even if all the citizens despise their leadership, they cannot coordinate without common knowledge.
“The smart way to keep people passive and obedient is to strictly limit the spectrum of acceptable opinion but allow very lively debate within that spectrum….”
To his surprise, the emotional hue of a word can invert the meaning of a sentence. People often care less about the truth of their beliefs than the consequences of believing something for fear of being ostracized from their social group.