Holocaust survivors around the world are lending their voices to a campaign launched Wednesday targeting Facebook head Mark Zuckerberg, urging him to take action to remove denial of the Nazi genocide from the social media site.

Coordinated by the New York-based Conference on Jewish Material Claims Against Germany, the #NoDenyingIt campaign uses Facebook itself to make the survivors’ entreaties to Zuckerberg heard, posting one video per day urging him to remove Holocaust-denying groups, pages and posts as hate speech. Videos will also be posted on Facebook-owned Instagram, as well as Twitter.

Zuckerberg raised the ire of the Claims Conference and others with comments in 2018 to the tech website Recode that posts denying the Nazi annihilation of 6 million Jews would not necessarily be removed. He said he did not think Holocaust deniers were “intentionally” getting it wrong, and that as long as posts were not calling for harm or violence, even offensive content should be protected.

After an outcry, Zuckerberg, who is Jewish himself, clarified that while he personally found “Holocaust denial deeply offensive” he believed that “the best way to fight offensive bad speech is with good speech.”

Since then, Facebook representatives have met with the Claims Conference but the group, which negotiates compensation payments from Germany for Holocaust victims, says Zuckerberg himself has refused to. The goal of the campaign is to get him to sit down with Holocaust survivors so that they can personally tell him their stories and make their case that denial violates Facebook’s hate speech standards and should be removed.

“In Germany or in Austria people go to prison if they deny the Holocaust because they know it’s a lie, it’s libel,” said Eva Schloss, an Auschwitz survivor who today lives in London and has recorded a message for Zuckerberg.

“How can somebody really doubt it? Where are the 6 million people? There are tens of thousands of photos taken by the Nazis themselves. They were proud of what they were doing. They don’t deny it, they know they did it.”

Schloss’ family escaped before the war from Vienna to the Netherlands, where she became friends with Anne Frank, who lived nearby in Amsterdam and was the same age. After the German army overran the country, the Schloss and Frank families went into hiding but were discovered by the Nazis separately in 1944, the Schloss family betrayed by a Dutch woman.

Schloss and her mother survived Auschwitz, but her father and brother were killed, while Otto Frank, Anne’s father, was the only survivor of his immediate family and married Schloss’ mother after the war. Otto Frank published his daughter’s now-famous diary so that the world could hear her story. Schloss has written about her own story, is a frequent speaker and would like to tell Zuckerberg of her own experience.

“It was just every day, the chimneys were smoking, the smell of burning flesh,” the 91-year-old told The Associated Press, adding that she had been separated from her mother and assumed she had been gassed.

“Can you imagine that feeling? I was 15-years-old and I felt alone in the world and it was terrible.”

Facebook said in a statement that it takes down Holocaust denial posts in countries where it is illegal, like Germany, France and Poland, while in countries where it is not an offense, like the U.S. and Britain, it is carefully monitored to determine whether it crosses the line into what is allowed.

“We take down any post that celebrates, defends, or attempts to justify the Holocaust,” Facebook told the AP. “The same goes for any content that mocks Holocaust victims, accuses victims of lying about the atrocities, spews hate, or advocates for violence against Jewish people in any way. Posts and articles that deny the Holocaust often violate one or more of these standards and are removed from Facebook.”

Earlier this month, a two-year audit of Facebook’s civil rights record found “serious setbacks” that have marred the social network’s progress on matters such as hate speech, misinformation and bias. Zuckerberg is one of four CEOs of big tech firms who face a grilling by the U.S. Congress on Wednesday over the way they dominate the market.

More than 500 companies on July 1 began an advertising boycott intended to pressure Facebook into taking a stronger stand against hate speech. The Claims Conference decided to launch its own campaign after concluding the boycott “doesn’t seem to be making a dent,” said Greg Schneider, the Claims Conference’s executive vice president.

Several Holocaust denial groups have been identified on Facebook by the New York-based Anti-Defamation League, some hidden and most private.

On one, “Real World War 2 History,” administrators are clearly aware of the fine line between what is and isn’t allowed, listing among its rules that members must “avoid posts that feature grotesque cartoons that FB censors can construe as racist or hateful.”

Another page, the “Committee for Open Debate on the Holocaust,” features regular posts of revisionist videos, including one from February in which the commentator says the Zyklon B gas used to kill Jews in Nazi death camps was actually employed to kill the lice that spread typhus, claiming “this chemical was used to improve the inmates’ health and reduce, not increase, camp mortality.”

Though not overtly advocating attacks, such postings are meant to “perpetuate a myth, anti-Semitic tropes that somehow Jews made this up in order to gain sympathy or political advantage” and could easily incite violence, Schneider said.

“The United Nations has acknowledged that Holocaust denial is a form of anti-Semitism, and of course anti-Semitism is hate speech,” he said.

For Charlotte Knobloch, a prominent German Jewish leader who survived the Holocaust in hiding as a young girl and is participating in the campaign, it is particularly important for social media platforms to be vigilant about preventing denial because many in younger generations rely on them for information.

“They have a particular responsibility,” the 87-year-old told the AP.

(AP)