https://www.vox.com/recode/2020/11/4/21548733/trump-stolen-election-twitter-facebook-label

Democrats have worried that Trump would declare a premature victory via social media.

Twitter and Facebook both labeled a post President Trump shared at the end of Election Day in which he baselessly said the election is being “stolen” from him. Twitter took more aggressive action by warning users that the post is “potentially misleading” and slowing its reach; Facebook posted a label saying that ballots could take days or weeks to count.