The authors attempt an explanation of how our military branches of government together with film distributors shape what films are heavily promoted and Americans allowed to see. This results in films that are seriously critical of government actions and policies but result in very limited distribution and, in turn, incur financial losses to their promoters. However, I believe the authors' attempts at explanation fall well short of reality, and this is likely because of their own indoctrination received in schools controlled by the ruling capitalist class.
You see, during and especially after WWII, American fascist capitalists came out of the woodwork of "isolationism" of the 1930s and allied themselves with the devastated remains of the British Empire to establish a new US-led Empire. The Zionist Jews soon joined them after they took control of Palestine in 1948. Immediately after the war when the old-fashioned fascist powers (Germany, Italy, and Japan) were successfully concluded, they moved aggressively in all institutions to bring the American people along with them in support of their imperial ambitions. They infiltrated labor unions, higher educational institutions, and Hollywood (prove it, you might say. I simply don't have the staff and time to do this, and my old age also has diminished my energy) as their main initial targets in this campaign. After that they infiltrated media corporations and every other institution that could conceivably have independent influences that were anathema to their imperial ambitions.
They also moved successfully to hide all of these actions from view by ordinary Americans. The fascist American, British, and Zionist capitalists stayed hidden in a deep state where no one was allowed to identify them and examine what they were doing. The most visible heads were those connections with the CIA: Allen Dulles, James Angleton, and George H. W. Bush. Meanwhile, abroad they brought areas they militarily controlled after WWII under ideological control mainly through such actions as Operation Gladio, and the same control of media and other institutions as they did within the USA.
I have provided some general references below. I have "tons" of other saved online documents, but I don't want to overwhelm you. (Notice that some have been taken down, or for some other reason eliminated. I have noticed this recently and it has been increasing. The Tides Foundation which funnels money from various sources to fund propaganda outlets is no longer providing access to data about funding particular websites. I used them in approximately 2011 to find out that they were funding Amy Goodwin of Democracy Now around $200,000. Thus, she avoids topics like 9/11 and limits other coverage.)
I think we must be conscious that the fascists of today's capitalist world have learned a lot of lessons from the earlier fascists of the 1930s and 40s. As is mentioned in the article, they strenuously avoid the appearance of old-fashioned propagandists. Thus, they permit some very limited criticisms and left-wing views to be exposed to the public, but this is extremely limited and mostly quite innocuous to their interests. They have all kinds of means to limit such criticisms and leftist views by their control of media, film industry, and co-opting people with their control over careers and with lots of money.
70 Years of Disinformation: How the CIA Funded Opinion Magazines in Europe - American Herald Tribune
The CIA and the Media: Bernstein
The book “Bought Journalists” 5 People You Won’t Believe Worked For the CIA - YouTube
Mainstream Media: Presstitutes for the Rich and Powerful
Operation Mockingbird - Wikipedia ‘German politicians are US puppets’ | Oriental Review
Is The West A Capitalist Society? -- they pretend to be independent reporters
Rachel Maddow Plays Glenn Beck
Shaky Foundations: Toxic Sources, Tainted Money
Oil Sands Truth: Shut down the Tar Sands
US military studied how to influence Twitter users in Darpa-funded research
Why has Time magazine endorsed the #MeToo “revolution”?
Government has order the media not to cover 9/11
Article: The Cointelpro Role of Left Gatekeeping Foundations | OpEdNews