An effective tactic to prevent people from looking into something is to promote obviously false information, bonus if it's offensive, and associate it with information that can be verified. Another related tactic is for people who have a long track record of promoting false information promote something that's verifiable. That way people will dismiss real information that has been associated with bs. There is a paper, by a good friend of mine on this "Discrediting By Association: Undermining the Case for Patriots Who Question 9/11", and links to much more info in my profile.
And I agree, there are many documentaries on modern issues that are pure junk.
And I agree, there are many documentaries on modern issues that are pure junk.