Here's a thing I was wondering about the other day.
There are things that probably everyone here would agree upon - as an easy example, let's just talk about Earth not being flat. There are people, online and offline, that disagree with this fairly simple fact, which might come from a misunderstanding of science, distrust in the establishment, something like that.
My question is - how much should we dignify these people with discussions and responses? It is very unlikely for the minds of such people to be changed, no matter how much proof is thrown at them. It could be said that such cases are good mental exercise, but, more often than not, they are low hanging fruit that's so shaky that it's not even fun to disprove.
Could it be that giving these people the attention is causing more harm than good, from wasted time to other people starting to agree with them? And if so, how should we go about judging what beliefs are "OK" to discuss?