Political ads can lie if they want, Facebook confirms

Faced with a stark real-world test, though, Facebook appears once again to be erring on the side of letting misinformation circulate far and wide if a politician promotes it.

"If the claim is made directly by a politician on their Page, in an ad or on their website, it is considered direct speech and ineligible for our third-party fact checking program," the company added.

While the guideline used to say that ads "must not contain deceptive, false, or misleading content," the rule now prohibits ads "that include claims debunked by third-party fact checkers" or, in some circumstances, by third-party organizations "with particular expertise" in the matter.