We live in the age of distributed truth, and it's an environment in which fake news can spread like mold when in viral form. But the same applies to the truth, and if there's one lesson on how to do your part in an age of distributed truth, it's to speak the truth and to support those who do. post 
In Rational Ritual, the concise, readable, and seminal text on the subject of common knowledge, it is described this way: "...knowledge of the message is not enough; what is also required is knowledge of others’ knowledge, knowledge of others’ knowledge of others’ knowledge, and so on — that is, common knowledge.”
The internet gave everyone a megaphone, and these days that can feel like that Chinese proverb, you know the one. Perhaps the truth was better kept in the hands of a limited set of responsible stewards, but that age of the expert has passed, and that system had its own issues. As every Death Star reminds us each time they're blown up, concentrating power in a small area has its own unique vulnerability.
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See Plural Identity for reports on the psychology of long-running conflicts.
See Moral Agent's Club where Dennett suggests value in rules and punishments for their violations.