SAN FRANCISCO, WASHINGTON • Facebook chief executive Mark Zuckerberg said the United States presidential election on Tuesday will be a test of four years of work and adjustment by the social network to root out foreign interference, voter suppression, calls for violence and more.
"Next week will certainly be a test for Facebook," he added in a conference call on Thursday to discuss quarterly earnings.
"Election integrity is and will be an ongoing challenge. And I'm proud of the work that we have done here."
His company has faced intense criticism since the 2016 election, when Russian operatives used Facebook and Instagram to circulate misinformation and stoke discord - efforts that took months to discover.
Mr Zuckerberg said the company has come a long way since then, taking down 100 similar coordinated networks from Russia, China, Iran and elsewhere, and has built better systems to detect fake identities.
The company sought to close loopholes in data sharing that were revealed in the scandal over Cambridge Analytica, the consulting firm that in 2016 used targeting data improperly obtained from Facebook quizzes.
Recently, Facebook has got more directly involved in what kind of content its users see, encouraging millions to sign up to vote and directing people to an information centre with verified details from election officials.
Still, with 2.74 billion monthly users, the social network will likely find it hard to stay ahead of all the ways its platforms could be used by bad actors.
Mr Zuckerberg predicted violence could come from some of the groups that have organised on Facebook and were removed only recently.
"I'm worried that with our nation so divided, and election results potentially taking days or weeks to be finalised, there's a risk of civil unrest across the country," he said on the call. "Given this, companies like ours need to go well beyond what we've done before."
On Thursday, Facebook-owned Instagram said it was making changes to its image-sharing platform to prevent the spread of misinformation.
For users in the US, Instagram will temporarily remove the "Recent" tab from hashtag pages starting on Thursday, it said in a statement on Twitter.
"We're doing this to reduce the real-time spread of potentially harmful content that could pop up around the election," the statement added. Instagram's "Recent" tab arranges hashtags in chronological order and amplifies content.