Facebook came under fresh criticism Tuesday for its hands-off approach to political speech, as a group of employees and US lawmakers called on the social network to apply fact-checking for politicians spreading misinformation.
A letter from Facebook employees urged the company to crack down on "civic misinformation," saying the spread of debunked claims is a "threat" to what the company stands for.
"We strongly object to this policy as it stands. It doesn't protect voices, but instead allows politicians to weaponise our platform by targeting people who believe that content posted by political figures is trustworthy," said the letter first obtained by the New York Times, which said some 250 employees had endorsed it.
At the same time, US lawmakers critical of Facebook stepped up their calls to revisit its policy, which exempts comments and paid ads on the platform from fact-checking - an issue that has become heated with President Donald Trump's online ads using what some called "provably false" claims.
"Facebook's new ads policy allows politicians to run demonstrably false advertising on its platform. I don't think that's right," said Senator Mark Warner, a Virginia Democrat who added that he sent a letter to Facebook chief executive Mark Zuckerberg calling on him "to reverse this decision."
Other Democrats joined the effort, welcoming the letter from Facebook employees.
"Being a politician shouldn't be a license to lie - especially to spread hatred. If Facebook employees get it so should Zuckerberg," tweeted Senator Richard Blumenthal.
Those comments were echoed by Senator and presidential hopeful Elizabeth Warren, who tweeted: "Facebook's own employees know just how dangerous their policy allowing politicians to lie in political ads will be for our democracy. Mark Zuckerberg should listen to them - and I applaud their brave efforts to hold their own company accountable."
Facebook did not respond to an AFP query, but Zuckerberg earlier this month articulated Facebook's policy, saying it's not the job of tech firms to "censor" politicians.
Zuckerberg said the policy is based on a long tradition of allowing free expression.
"I don't think most people want to live in a world where you can only post things that tech companies judge to be 100% true," he said.
The policy on Facebook, and a similar approach from other platforms such as Twitter, creates a challenge for online firms seeking to avoid the role of being an "arbiter" of truth and entering the fray of politics.