Facebook, finally enacting a measure long called on by critics, said it will prohibit any content that “denies or distorts the Holocaust.”

Facebook CEO Mark Zuckerberg, in a post Monday announcing the policy change, said he has “struggled with the tension between standing for free expression and the harm caused by minimizing or denying the horror of the Holocaust.”

“My own thinking has evolved as I’ve seen data showing an increase in anti-Semitic violence, as have our wider policies on hate speech,” Zuckerberg said. “Drawing the right lines between what is and isn’t acceptable speech isn’t straightforward, but with the current state of the world, I believe this is the right balance.”

That’s a stark reversal from Zuckerberg’s previous position on the issue. In 2018, he said in a Recode interview, “I’m Jewish, and there’s a set of people who deny that the Holocaust happened. I find that deeply offensive. But at the end of the day, I don’t believe that our platform should take that down because I think there are things that different people get wrong.”

The social-media giant made the decision based on the “well-documented rise in anti-Semitism globally and the alarming level of ignorance about the Holocaust, especially among young people,” Monika Bickert, Facebook’s VP of content policy, wrote in a blog post Monday. She noted that Facebook also recently banned anti-Semitic stereotypes “about the collective power of Jews that often depicts them running the world or its major institutions.”

Bickert specifically cited a recent survey of U.S. adults 18-39 that found almost one-fourth said they believed the Holocaust either was a myth, that it had been exaggerated or they weren’t sure it actually happened. About 63% of respondents did not know that 6 million Jews were exterminated by the Nazi regime, and 36% thought the number of those murdered was “2 million or fewer” per the survey, commissioned by the Conference on Jewish Material Claims Against Germany.

Starting later n 2020, Facebook will direct users who search for terms associated with the Holocaust or its denial to “credible information” from third-party sources, according to Bickert.

Facebook’s announcement that it is banning Holocaust denial content comes after it was targeted by the Stop Hate for Profit campaign, launched by groups including the NAACP, Common Sense Media and the Anti-Defamation League. The initiative was joined by hundreds of companies who pledged to suspend advertising on Facebook-owned platforms temporarily, with the goal of spurring the company to more aggressively block hate speech on its services.

“By taking the critical step to remove Holocaust denial content, Facebook is showing that it recognizes Holocaust denial for what it truly is: a form of antisemitism and therefore hate speech,” World Jewish Congress president Ronald S. Lauder said in a statement.

The ADL said it has been urging Facebook since 2011 to classify Holocaust denial on its platform as a form of hate speech.

“Whatever forces led Facebook to make this decision, we believe it will have a positive impact on the experience of Jewish users on their platform,” ADL CEO Jonathan Greenblatt said in a statement. “While we are relieved to learn this news, we also would note that platform decisions of this nature are only as good as the companies’ enforcement. Facebook now needs to reassure the global community that it is taking meaningful and comprehensive steps to ensure that Holocaust deniers are no longer able to take advantage of Facebook’s various platforms to spread antisemitism and hate.”

To date, Facebook has banned more than 250 white supremacist organizations and last week prohibited all content from groups affiliated with QAnon, the pro-Trump conspiracy and disinformation movement that has sprung up on the last three years. In the second quarter of 2020, Facebook removed 22.5 million pieces of hate speech from its platform in the second quarter of this year.

Meanwhile, Facebook still has a major misinformation problem — and, in fact, users engage with misleading or false information today more than three times as much as they did leading up to the 2016 U.S. election, according to a new study from public-policy think tank German Marshall Fund.

The study found that overall on Facebook, likes, comments and shares of articles from news outlets that “repeatedly publish verifiably false content” has increased 102% from Q3 of 2016 to the third quarter of 2020. In addition, Facebook user engagement with content from publishers that “fail to gather and present information responsibly” — especially Fox News, Daily Wire and Breitbart News — has grown 293% over the same time period, per the German Marshall Fund study.