Facebook says it does not fact check politicians' statements on its site, even if they might be false. The social network operator says that's because such statements could be newsworthy and it doesn't want to act as a "referee" for political debates.
Facebook works with third-party fact checkers, including The Associated Press, to weed out misinformation, such as false news and manipulated photos and videos.
But Nick Clegg, Facebook's vice president of global affairs, said the company has exempted politicians' posts from its fact-checking program for more than a year. But if politicians share previously debunked links or other material, those will be demoted and banned from being included in ads.
"At Facebook, our role is to make sure there is a level playing field, not to be a political participant ourselves," Clegg said, according to a transcript Facebook posted on its website of his speech at the Atlantic Festival in Washington on Tuesday.
Twitter also has a newsworthiness exemption in its policy that adds warning labels to politicians' tweets if they violate the service's rules but involve matters of public interest. Before the policy was enacted in June, Twitter exempted prominent leaders from many of its rules, contending that publishing their controversial tweets helps hold them accountable and encourages discussion.
Critics say treating politicians' speech differently gives them a free pass to spread hate, abuse and misinformation.