The US Justice Department has launched an unprecedented investigation into Wikipedia, threatening the online encyclopedia’s nonprofit status amid accusations that the site has become a platform for anti-Israel propaganda and foreign influence operations.

“It has come to my attention that the Wikimedia Foundation, through its wholly owned subsidiary Wikipedia, is allowing foreign actors to manipulate information and spread propaganda to the American public,” Interim U.S. Attorney for the District of Columbia Edward Martin wrote in a four-page letter to the Wikimedia Foundation.

“Wikipedia is permitting information manipulation on its platform, including the rewriting of key historical events and biographical information of current and previous American leaders.”

While the letter broadly challenges Wikipedia’s neutrality, at the heart of Martin’s investigation are allegations that Wikipedia has harbored a systematic bias against Israel. According to investigations by Pirate Wires and Jewish Journal, high-ranking Wikipedia editors have engaged in systematic efforts to portray Israel negatively while softening depictions of terrorist organizations. The cohort removed mentions of Hamas’s 1988 charter calling for the massacre of Jews and edited articles to describe Zionism as an “ethnocultural nationalist movement” pursued through “colonization.”

The Anti-Defamation League lent credibility to these concerns in March when it published a report titled “Editing for Hate: How Anti-Israel and Anti-Jewish Bias Undermines Wikipedia’s Neutrality,” which claimed that “at least 30 Wikipedia editors acted in concert to circumvent Wikipedia’s policies to introduce antisemitic narratives, anti-Israel bias, and misleading information.”

“Most readers assume Wikipedia is a reliable online encyclopedia, but in reality, it has become a biased platform manipulated by agenda-driven editors on many topics,” ADL CEO Jonathan Greenblatt said.

Wikipedia’s bias further intensified following Hamas’s October 7, 2023 attack on Israel. Editors created new articles with loaded titles like “Gaza Genocide,” which claimed that “according to a United Nations special committee, Amnesty International, and other experts and human rights organizations, Israel is committing genocide against the Palestinian people.” Another article titled “Israeli Apartheid” asserted that Israel had built “a system of institutionalized segregation and discrimination.”

Martin’s letter also expressed concern about how this alleged manipulation could have far-reaching consequences, noting that top search engines prioritize Wikipedia results and artificial intelligence platforms use Wikipedia data to train language models.

Wikipedia disputed the allegations in a statement released Friday, emphasizing that it’s content is governed by policies ensuring information is presented “as accurate, fair and neutral as possible” with nearly 260,000 volunteers participating in the editorial process. Critics have also pointed out that investigations into tax-exempt status are typically handled by the IRS and not federal prosecutors.