Eighty percent of the content identified by a prominent study on antisemitism across major Internet platforms like Facebook and YouTube remains on the Web today, the Online Hate Prevention Institute reported this week.

This amounted to about 1,620 “unique items of social media content” reported by users as antisemitic, using a tool launched by the Australian government to measure the response to online antisemitism.

“This demonstrates a significant gap between what the community understand to be antisemitic, and expects to be a violation of community standards which prohibit hate speech, and what social media platforms are currently willing to remove,” said the study, which was authored by Australian-based Dr. Andre Oboler on behalf of the Global Forum for Combating Antisemitism.

According to the study, YouTube had the highest levels of antisemitic content, at 41 percent of the sample, followed by Twitter (36%) and then Facebook (23%). YouTube was also by far the least likely of the three to respond to user complaints, leaving in place the vast majority of antisemitic content circulating on the web after 10 months and rising to a 47% share of the antisemitic content online at the end of the study.

Facebook had the highest rate of removal of antisemitic content, taking down 37% of reported instances, which was followed by Twitter (22%) and then YouTube at just 8%. The study also indicated, however, that YouTube and Twitter attract more hate content than Facebook.

The study also broke down antisemitism into two categories — traditional and new antisemitism. Traditional antisemitism “accounts for items like conspiracy theories, antisemitic tropes, and racist slurs,” and made up a 49% share of the hate content. New antisemitism, “where the State of Israel and Jewish people by association are demonized,” accounted for 34%. Also included in the study were Holocaust denial (12% of content) and content inciting to violence against Jews (5%).

The so-called new antisemitism was less likely to be taken down across the social media platforms than either traditional antisemitism, Holocaust denial or calls to violence.

The study said that “action is needed to close the gap between the informed public and expert understanding of antisemitism and the existing understanding of the social media platforms.”

The study was meant to prepare for this year’s Global Forum for Combating Antisemitism, which was last held in May 2015.