https://techcrunch.com/2020/05/26/twitter-trump-labels-fact-checking-tweet/

On the heels of a furor over his tweets accusing MSNBC host Joe Scarborough of murder, Twitter has quietly begun to fact-check the president.

A new warning label encouraging Twitter users to “Get the facts about mail-in ballots” appeared on a series of tweets in which the president baselessly claimed ballots received through mail-in voting methods are “fraudulent.”