Facebook says it will label rule-breaking posts after advertisers flee

Facebook says it will flag all "newsworthy" posts from politicians that break its rules, including those from President Donald Trump, and will ban false claims meant to discourage voting, the company said Friday.

CEO Mark Zuckerberg had previously refused to take action against Trump posts suggesting that mail-in ballots will lead to voter fraud. Twitter, by contrast, slapped a "get the facts" label on them.

"We will soon start labeling some of the content we leave up because it is deemed newsworthy, so people can know when this is the case," Zuckerberg wrote in a post on Friday explaining the policy change. "We'll allow people to share this content to condemn it, just like we do with other problematic content, because this is an important part of how we discuss what's acceptable in our society — but we'll add a prompt to tell people that the content they're sharing may violate our policies," 

Zuckerberg also shared specific examples of voter-suppression content that would get taken down, including posts suggesting that Immigration and Customs Enforcement will be checking papers at polling sites. 

Threats of "coordinated interference," such as a post saying "My friends and I will be doing our own monitoring of the polls to make sure only the right people vote," will also be removed, Zuckerberg said.

Facebook announced the new policy after a dozen heavyweight advertisers said they were pulling ads from the platform in response to its divisive and sometimes hate-promoting content. 

On Thursday, Verizon joined several mid-sized companies in the Facebook boycott organized by prominent civil right groups. Then came Unilever: The Anglo-Dutch consumer-goods giant that owns brands including Ben & Jerry's ice cream, Dove soap, Hellmann's mayonnaise and Lipton tea, became the latest company to pull its ads on Friday. 

Unilever said the polarized atmosphere in the United States ahead of November's presidential election placed responsibility on brands to act, and said it would stop advertising on Facebook and its Instagram subsidiary Instagram as well as Twitter at least until the end of the year.

Shares of both Facebook and Twitter fell roughly 7% following Unilever's announcement.

Sarah Personette, vice president of global client solutions at Twitter, said the company's "mission is to serve the public conversation and ensure Twitter is a place where people can make human connections, seek and receive authentic and credible information, and express themselves freely and safely."

She added that Twitter is "respectful of our partners' decisions and will continue to work and communicate closely with them during this time."

CBS News' Irina Ivanova contributed reporting.