This is related to a topic I have been writing a book about, so it is something I have spent hundreds of hours researching. The manipulation within both social media and search engine companies is troubling and this movie begins to scratch the surface.
You can test this manipulation yourself; you don't have to rely on the claims of others. Search any topic related to the president on Google. Choose one of the positive accomplishments of his administration or one of the policies that have helped reduce taxes or shorten prison sentences. What you will be faced with, in the search results, will not be articles and content describing those positive results, but instead, all negative articles written by those who loathe the president and his administration. If you agree with the content creators, these results might not bother you; but consider the manipulation. It controls the messaging. It causes you to think in one way despite any positive outcomes. It is a form of brainwashing.
This manipulation applies to any social issue as well. Search any current social issue and take note of what content is included on the first pages of the search results. Do those results look random and representative of a cross section of opinion or do they all seem to represent one viewpoint?
This topic could be a movie into itself. What people believe may not be real, or balanced, if they depend on the Internet and search for information.
Almost all control of the Internet and nearly all social media originate from one small portion of the country about 30 miles in total area. If everyone in that area accepts the same ideology, how can you expect to get accurate, unbiased information from social media or search?
Think about it.