The control of the dissemination of information by corporate media is one of the most powerful methods that the ruling capitalist class uses to shape society in its interest of profit and power. Other means are indoctrination in their schools and more subtly in their entertainment industries. Hence the importance of alternative, independent media (mostly the internet, but also books) by people who have an allegiance to truth and not to ruling class interests.
Although Todhunter in this excellent, well-documented article makes reference to mainstream media in Britain where he has lived most of his life, of course the same observations apply to media in the US--maybe even more so.
...that’s the role of the [mainstream corporate] media: to help reinforce and reproduce the material conditions of a divisive social system on a daily basis. It’s called having a compliant, toothless media. It’s what the corporate media itself calls part of ‘liberal democracy’. And in this type of 'liberal democracy', it is people like Edward Snowden or Julian Assange who expose the wrongdoings of the political-corporate elites that are hounded.