Echo chambers aren’t bad in and of themselves. They can be fine in the context of, say, a safe space for LGBTQ where they don’t have to deal with people who want to debate their very existence. They can also be good for developing ideas where everyone’s already on the same page. But echo chambers are problematic when there is little to no crossover between echo chambers. They produce a fractured, tribalistic society where ideological rivals are dehumanization and reduced to existential-level enemies. That’s happening right now in the United States, and it is a major driver behind the paralysis in our politics.