Alfred Korzybski, the father of general semantics, first uttered what must now seem like a well-worn phrase: "The map is not the territory." And yet, I don't think this view has yet been well-incorporated into human culture.
In a time when social media outlets are trying to sort what is "fake" from what is "genuine" or "true," very little thought is being put into what we even mean by "fake," "genuine" or "true." Facebook, for example, has resorted to third-party fact-checkers, a mix of news organizations and fact-checking nonprofits. It is also hiring thousands of new employees to check what it calls "non-news" information posted on Facebook pages.
A lot of checking revolves around whether someone said or did what is claimed. That's not too hard. The next level involves the effect of a policy or position. That's more difficult since some of the policies in question aren't in effect and even for those that are, it is always hard to trace cause and effect from a policy to a specific result.