It's difficult to tell, among all of the conflicting voices in the world, who is right. But some people are just agents of chaos in this endeavor: the ones who will present things they only just heard as facts, those who present as certainties those things of which they are actually uncertain, those who conflate the plausible and the probable, and those who just pick ideas off the ground and wear them unexamined.
Don't believe a word they say.
That said, I'm not actually sure what to do with them. I want to help them learn to care more about the difference between truth and rumor, but these people are often offended when I question their rigor. Let me know if you have any ideas.