Fact-checking has become partisan. Can it survive the backlash from conservatives and Big Tech?

In a coffee-table book published last year about his first term in office, U.S. president-elect Donald Trump threatened to jail Mark Zuckerberg, suggesting the Meta CEO had helped rig the 2020 election.

The conspiracy theory had circulated widely on social media, including on Meta's own platforms, Facebook and Instagram. It was eventually debunked by one of the third-party groups that Meta paid to fact-check popular content on its sites.

On Tuesday, Zuckerberg announced an abrupt end to Meta's fact-checking program in the U.S., drawing praise from Trump.

Zuckerberg's move appeared aimed, in part, at shielding Meta from an escalating effort by Republican lawmakers and activists to cripple the fact-checking industry that has arisen alongside social media.

It's also causing a reckoning among fact-checkers themselves about the value and effectiveness of their work amid the daily tidal wave of falsehoods.

"Fact-checking has been under attack. It's been made into a bad word by some corners of our politics in the U.S. and around the world," said Katie Sanders, editor-in-chief of PolitiFact, which until this week had been one of the partners in Meta's fact-checking program. 

"We're still in the very earliest stages of untangling the implications. But there's anxiety in the air, for sure."

Fact-checking has been a routine feature in news media since at least the 1930s.

But as social media platforms grew in popularity in the 2000s, there emerged a number of publications — such as FactCheck.org and PolitiFact — dedicated almost entirely to verifying the statements of public figures. 

The election of Donald Trump in 2016, however, proved to be a watershed moment for this emerging industry. 

The candidate's penchant for uttering falsehoods, alongside concerns about social media being used by foreign actors to manipulate public opinion, generated intense pressure on companies like Facebook to take action. 

Facebook entered into partnership agreements with several fact-checking outlets to review content it flagged as potentially misleading. The program eventually expanded to around 130 other countries, including Canada. 

"People really thought, let's just label it. We should just tell people what's false, what's not, and that's going to solve the problem," said Katie Harbath, a former director of public policy at Facebook. 

"But immediately there were challenges with the fact-checking program. They're not able to do it quickly and they're not necessarily able to do it at scale."