Trump made false claims about vote-by-mail on Facebook and Twitter. Here's why the tech companies won't ban him or take down the posts.

• On Facebook and Twitter this week, President Donald Trump and his campaign have claimed without evidence that vote-by-mail programs are a conspiracy to commit voter fraud.
• States including Nevada, Michigan, and Georgia have informed voters about how to vote by mail as COVID-19 continues to spread. There's no evidence of voter fraud schemes, and Michigan's secretary of state called Trump's claims "misinformation."
• Facebook and Twitter have policies meant to fight misinformation about elections, but both platforms determined that Trump's claims don't violate their policies. Here's why.

President Donald Trump attacked states that are letting people vote by mail amid the COVID-19 pandemic this week, implying in a series of tweets and Facebook ads that mail-in ballots are akin to voter fraud and falsely claiming that the states' actions are "illegal."

States including Nevada, Michigan, and Georgia have started sending voters information about how to vote by mail, which may prove a safer option than in-person voting as COVID-19 continues to spread. There's no evidence to suggest that mail-in ballots correlate with voter fraud, and Trump himself voted by mail in 2018 and 2020.

On Wednesday, Trump falsely claimed that Michigan's secretary of state "illegally" sent out absentee ballot applications. The action was not illegal and state officials called Trump's claim "misinformation." Meanwhile, Trump's 2020 campaign bought hundreds of Facebook ads this week claiming without evidence that Democrats are "stuffing the ballot boxes with FAKE and FRAUDULENT votes."

Facebook and Twitter both have policies against spreading misinformation, especially as it relates to voting and elections. After Facebook was harshly criticized for the spread of misinformation on the platform leading up to the 2016 election, the company rolled out a slate of new policies meant to "protect the 2020 US elections," including rules against ads that discourage voting. Twitter's election integrity policy similarly bans misleading information about how to vote and voter suppression, and Twitter CEO Jack Dorsey has claimed that the platform will ban Trump if he violates its rules.

But both platforms determined that Trump's false claims about vote-by-mail this week don't violate their policies and will be allowed to remain up on their respective sites.

A Twitter spokesperson told Business Insider that the company determined Trump's tweets don't directly try to dissuade people from voting, so they won't be taken down.

Facebook did not immediately respond to a request for comment. But in the past, Facebook has hewn to its controversial policy against fact-checking political figures' ads, and that policy appears to sheild the Trump campaign's misleading ads purchased this week.

Facebook's policy allowing false claims in political ads has received backlash both within and outside the company. CEO Mark Zuckerberg defended the decision as a way to protect free speech, but a group of Facebook employees pushed back on that reasoning in a letter last fall, arguing that "free speech and paid speech are not the same thing."