That reluctance to check ads is leading to concerns, including from those investigating Facebook. The head of parliamentary hearings looking into Facebook's practices, MP Damian Collins, told CNN that people shouldn't be allowed to spread false claims "just because they are paying" for it. He was also disappointed in former UK politician Nick Clegg, arguing that he hadn't made a "positive difference" as Facebook's Global Affairs VP.

It's not certain that Facebook's policy will create problems, especially when the election is happening on short notice. If there is evidence that politicians' false ads played a role, though, it could increase pressure on Facebook to alter its policies ahead of the 2020 US elections.