I like the content of this video - it has a lot to say about the way people en masse can be manipulated. It needs to be absorbed in a critical way of course, but I'm quite convinced that we humans are prone to psychic epidemics, and that they are much harder to resist than those caused by infections. I think that hysteria is a response to fear, and that fear in large groups of people is vulnerable to fake news that amplifies the collective fear. It makes more sense to me to tackle the underlying fears rather than attack the reaction.
Hysteria is a loaded term of course, and is itself one of those fear words designed to ramp up the tensions. I think it makes more sense to talk about collective anxiety in our societies rather than hysteria - and save that word for the most extreme situations.