Years ago a writer friend of mine asked me about and idea of how a group of people all doing the same thing at the same time could do the most damage in general

Years ago a writer friend of mine asked me about and idea of how a group of people all doing the same thing at the same time could do the most damage in general. I surely did not have good enough ideas for a writing, but this pizzagate thing seems to be one terrifying answer to that inquiry. Just that in this case the damage is very concentrated and it seems to affect only on a few group of people.