Owners of Facebook stock were rebuffed on Thursday after they called on company leaders to share more information about what they are doing to address the circulation of fake news.
They asked the firm to prepare a report on the subject.
Facebook maintained a report was unnecessary and would not benefit the company.
The proposal, presented at the firm’s annual meeting, did not pass. That was expected, since chief executive Mark Zuckerberg controls a majority of the firm’s voting power.
But Mr Zuckerberg addressed the issue as part of his remarks, pointing to the steps the firm has already taken, including making it harder for fake news spammers to make money from ads.
The firm has said it is experimenting with its news feed and testing new features to make it easier to report questionable posts. It also announced plans to hire 3,000 more people to monitor posts.
Mr Zuckerberg said the firm expects to invest more in artificial technology, but the technology is not “100% there yet”.
“The right way to go about this problem is to fight information with more information,” he added.
Facebook faced a backlash after the 2016 US presidential election, when studies found false news was widely viewed through the social media site.
Mr Zuckerberg was initially dismissive that fake news shaped the outcome of the election. But the firm has since conceded that it observed propaganda efforts by governments.
Natasha Lamb of Arjuna Capital, who presented the fake news proposal at the annual meeting, said Facebook cannot afford to think of itself as a neutral platform.
She called the steps Facebook has taken “too little, too late”.
“Investors seek assurance that fake news, fabricated content and hate speech is being handled responsibly over time,” she said.
Company leaders during the question and answer session said they knew fake news was a turn-off for users. They said investors should expect more announcements related to the issue.