How bad is anti-Semitism online? It’s getting harder and harder to know.

As the war between Israel and Hamas flooded social media with violent content, false information and a seemingly limitless wave of opinion, lawmakers and users have accused platforms like TikTok and Facebook of promoting biased posts.

Tech giants have denied the allegations. TikTok, accused of elevating pro-Palestinian content, blamed “flawed analysis” of hashtag data. Some Instagram and Facebook users circulated a petition accusing the platform’s parent company, Meta, of censoring pro-Palestinian posts, which Meta attributed to a technical bug.

Anti-Semitic content swarmed to X, the platform formerly known as Twitter and run by billionaire Elon Musk. This is what the CEO of X, Linda Yaccarino, says in a message on Thursday about anti-Semitism that “there is no place for it anywhere in the world.”

However, according to academic researchers and interest groups, it is difficult to find out where the truth lies. They said the debates over content related to the war between Israel and Hamas have highlighted the roadblocks that hinder independent analysis of what appears on major online services. Instead of being able to methodically research online discourse, they must try to understand its scope and effects using inefficient and incomplete methods.

The ambiguity allows people to make dubious claims about what is dominant or popular online and allows the platforms to respond with similarly weak or distorted evidence, limiting accountability on all sides, the researchers said.

“We urgently need powerful, informed research on the actual impact of platforms on society, and we can’t do that if we don’t have access to data,” said Megan A. Brown, a PhD candidate. at the University of Michigan, who researches the online information ecosystem.

Inflammatory content – ​​and what to do about it – remained top of mind on social media platforms this week. More than a dozen Jewish TikTok creators and celebrities, including actors Sacha Baron Cohen and Debra Messing, confronted TikTok executives and employees in a private meeting over the platform’s handling of anti-Semitism and harassment. After Mr. Musk endorsed an anti-Semitic post on X, internal reports revealed that IBM had halted $1 million in planned advertising spending.

Researchers also tried to understand a surge of interest in a decades-old letter from Osama bin Laden. The so-called “Letter to America” criticized the United States and its support for Israel, repeated anti-Semitic tropes and condemned the destruction of Palestinian homes.

After reviewing public social media posts from Tuesday through Thursday, researchers from the Institute for Strategic Dialogue concluded that the number of references to the letter on X increased by more than 1,800 percent. They found 41 “Letter to America” videos with more than 6.9 million views on TikTok.

The researchers, Isabelle Frances-Wright and Moustafa Ayad, said in an interview that they wanted to do much more advanced analysis. Instead, they had to manually run searches using basic terms, which prevented them from analyzing the letter’s distribution by region or language.

“A lot of this content, especially video content, is not tagged with the type of text that we can manually search, so whatever we find is really just the tip of the iceberg,” Ms Frances-Wright said.

Jamie Favazza, a spokeswoman for TikTok, said the company supported independent research and gave access to more than 130 academic research teams to analyze the site. “We are working hard to soon expand access to civil society researchers in the US,” she said.

Meta declined to comment. X did not respond to a request for comment.

Background data on engagement, volume, and other metrics is typically retrieved through a platform’s application programming interface, or API. The big tech companies have long offered some level of access, but researchers say this now appears to be shrinking.

This year, as Mr. Musk sought new ways to make money with X, the company started charging thousands of dollars for monthly access to the API to block many researchers. Meta’s support for the data analysis tool CrowdTangle has shrunk amid internal concerns about damaging the company’s reputation.

Today, researchers say, the data they can study is often determined by what platforms choose to release — “consensual research,” some explained — and is often unreliable and delayed long past the point of relevance.

“With data you can always paint the picture you want, and you are the only one who has access to that data,” said Sukrit Venkatagiri, an assistant professor of computer science and disinformation expert at Swarthmore College. “If we don’t have a lens into what’s happening in these spaces with billions of users, it’s a little scary.”

TikTok has been at the center of the recent firestorm, in part due to its ownership by Chinese company ByteDance, with some critics claiming it encourages pro-Palestinian content to align with the government in Beijing. TikTok has been accused of amplifying pro-Palestinian videos through its powerful algorithmic feed and failing to tackle anti-Semitic content.

TikTok has issued multiple statements pushing back on accusations of bias, citing polls showing that young Americans supported the Palestinian cause before the company existed. The company has also tried to poke holes in data on popular hashtags that critics said revealed the service’s pro-Palestinian tilt.

This week TikTok said the hashtag #standwithIsrael had fewer videos than #FreePalestine, but “68 percent more views per video in the US, meaning more people are seeing the content.” It also pointed to public data on Instagram and Facebook, which showed millions of #FreePalestine posts and fewer than 300,000 #standwithisrael posts.