The answers sound reassuring: exposure to lies was rare for most users, and removing them did not measurably shift anyone’s beliefs. But, as a researcher who studies how misinformation permeates these platforms, I think the fine print matters more than the headline. For example, some 53 million Facebook accounts – 23% of users – received nearly 80% of content from untrustworthy sources. From around early November 2020, Meta deployed 63 emergency election measures aimed at reducing the flow of falsehoods for all users. One re-analysis of a companion study estimates these cut the share of untrustworthy content in ordinary feeds by around 24%.