Here’s a depressing dynamic I’ve seen a bunch the past two weeks:
(1) Crackpot conspiracy claim X is asserted, on the basis of supposed evidence Y.
(2) Y is decisively shown to be wrong.
(3) “OK, we can dismiss the claim that X.”
(4) No, you haven’t PROVEN not-X! It’s 50/50!

Once you’ve gotten a wildly implausible claim entertained on the basis of spurious evidence—a claim you’d have assumed was untrue by default—some people will now assume there’s a burden to disprove, or treat it as a coin flip, EVEN AFTER the "evidence” is debunked.

Concretely: “Voting software was rigged to steal the election!” By default you’d assume that’s not true absent strong evidence. Someone offers "evidence,” immediately shown to be bullshit. (A clerical error in Michigan that had literally nothing to do with software.)

Some people (I have discovered) do not therefore return to the prior default that this claim should be treated as false absent evidence. Now they think it’s equally likely to be true or false, or that the burden is on those who say it’s false to prove the negative.

Obviously some people are just going to swallow whatever fanfic flatters their priors; can’t help them. But this two-step seems to confuse at least some people who, before the bogus evidence, would have understood how “burdens of proof” work & correctly defaulted to “naw".

“DONALD TRUMP IS AN ALIEN LIZARD PERSON!”
That’s clearly not true.
"I HAVE VIDEO OF HIM REMOVING HIS LATEX SKIN!”
Really? OK wow… Wait… this video is just Rick Astley’s Never Going to Give You Up. So there’s only a 50 percent chance he’s a lizard person.

I’m sure there’s social psych research on this. But my anecdotal impression is that if you confuse people with spurious evidence, *even if they had a reasonably accurate prior probability*, you can nudge them into a sort of fail state of “P=.5” for arbitrary claims.