This is a very interesting question: when does a community become an echo chamber? To use the hunting example: I imagine sometimes the hunters talk about stuff to do with hunting itself; the merits of different rifles, or where to find game, or whatever. And this is a reasonable community discussion for them to have, and it wouldn't help to have activists shouting "hunting is evil" over conversations such as that.

But sometimes the hunters will talk about the politics of hunting: one will say, "those activists are wrong to complain about animals suffering, because <reasons here>", and then another will say "yes, it's so obvious they're wrong, because <reasons> are so obviously right", and the echo chamber is ringing - this is the situation where people ideally would be brought into contact with the opposing view.

Can an online community promote the first type of conversation while challenging the other? How would we set about that?