Facebook chief executive Mark Zuckerberg is standing by his decision not to challenge inflammatory posts by US President Donald Trump after staff members staged a rare public protest.
A group of Facebook employees - nearly all of them working at home due to the coronavirus pandemic - walked off the job on Monday.
They complained the company should have acted against Mr Trump's posts about protests containing the phrase "when the looting starts, the shooting starts".
Mr Zuckerberg told employees Facebook had conducted a thorough review and was right to leave the posts unchallenged, a company spokeswoman said.
She said Mr Zuckerberg also acknowledged the decision had upset many people working at the company.
On Friday, Twitter attached a warning label to a Donald Trump tweet about widespread protests over the death of African-American man George Floyd in Minnesota that included the same phrase.
Twitter said the post violated its rules against glorifying violence but was left up as a public interest exception, with reduced options for interactions and distribution.
Facebook declined to act on the same message, and Mark Zuckerberg sought to distance his company from the fight between the president and Twitter.
He maintained that while he found Mr Trump's remarks "deeply offensive", they did not violate company policy against incitements to violence.
One employee, who had tweeted his dissent on Monday, posted on Twitter his disappointment with Facebook executives.
"It's crystal clear today that leadership refuses to stand with us," Brandon Dail wrote.
Timothy Aveni, a junior software engineer on Facebook's team dedicated to fighting misinformation, announced on Monday he was resigning his position.
"Mark always told us that he would draw the line at speech that calls for violence," Mr Aveni wrote in a Facebook post.
"He showed us on Friday that this was a lie. Facebook will keep moving the goalposts every time Trump escalates, finding excuse after excuse not to act."
Civil rights leaders who attended an hour-long video call on Monday night with Mr Zuckerberg and top Facebook executives called the chief executive's explanations for allowing Mr Trump's posts to stay up "incomprehensible".
