I think there is a place for taking the time to fight against individual claims...but the thing you don't want to do is engage with the people who are not going to be convinced by anything...the people who have tied their identity and often even their livelihoods to believing that the government is trying to kill people (or something) because engaging with them only shines more light on them, and they will never run out of ways to move the goalposts and extend the argument. THAT'S THEIR JOB AND THEY LIKE IT!