TikTok recently pulled a tool that allowed researchers and others to study the popularity of hashtags on its app. The change, first reported by The New York Times, came shortly after researchers published a report using data from the tool that criticized the company.

As The New York Times points out, the tool was one of the few publicly-accessible methods of tracking details about the popularity of specific hashtags. TikTok, like other social media companies, has made it difficult for outsiders to track how content spreads in its app.

The tool in question is a feature called Creative Center, which provides data about the popularity of hashtags to would-be advertisers and others. Researchers at Rutgers’ Network Contagion Institute had used Creative Center’s search function to track hashtags deemed “sensitive” to Chinese government interests. The researchers compared the prevalence of the hashtags between TikTok and Instagram and concluded that many "sensitive" topics were "dramatically underrepresented on TikTok" compared with Instagram.

Soon after the report was published, the researchers said the search feature in Creative Center disappeared without an explanation. “Search capacity for Hashtags has itself now been removed from the user interface entirely, which NCRI discovered to have occurred on Christmas day, days after this report’s initial release,” they wrote in an addendum to the report. They added that TikTok had also disabled direct access to a number of “sensitive” topics they had previously tracked, including hashtags related to US politics and other geopolitical issues.

In a statement to The New York Times, TikTok confirmed the change. “Unfortunately, some individuals and organizations have misused the Center’s search function to draw inaccurate conclusions, so we are changing some of the features to ensure it is used for its intended purpose,” a company spokesperson said.

The dust-up is the latest example of mounting tensions between social media companies and researchers trying to study thorny topics like misinformation. Meta has also found itself at odds with researchers, and reportedly plans to deprecate CrowdTangle, a tool widely used by researchers and journalists to study how content spreads on Facebook. X has also greatly restricted researchers’ access to data since Elon Musk took control of the company, making its once open APIs prohibitively expensive to most groups.

In TikTok’s case, the company may be particularly sensitive to what it considers improper use of its tools. The company has for years denied that it aligns its content policies with the interests of the Chinese government as numerous government officials have called for the app to be banned. More recently, the company faced increased scrutiny over its handling of content related to the Israel-Hamas war — criticism that was also fueled by what the company said was an inaccurate portrayal of hashtag data.

That said, the company has made some concessions to researchers. TikTok began offering an official Research API to some academic institutions last year, and reportedly plans to make the tools available to some civil society groups that have questioned the company’s content moderation practices.

But for researchers, the move to abruptly cut off a tool will likely fuel more questions about just how willing the company is to work with them. “This lack of transparency is of deep concern to researchers,” the NCRI researchers wrote.

Newsletter platform Substack has removed "some" pro-Nazi publications from its platform following weeks of pressure over its content moderation rules.The takedowns include five newsletters flagged to the company by Platformer, which was first to report the news.

The move comes amid growing pressure on the newsletter company after it repeatedly declined to remove publications promoting white nationalist and pro-Nazi views. In November, The Atlantic reported that it found “scores of white-supremacist, neo-Confederate, and explicitly Nazi newsletters on Substack,” some of which were monetized by their authors.

Substack, which has landed in hot water over its refusal to ban Nazis in the past, responded to the article and ensuing controversy by doubling down on its stance. “I just want to make it clear that we don’t like Nazis either—we wish no-one held those views,” Substack cofounder Hamish McKenzie wrote in December. “But some people do hold those and other extreme views. Given that, we don't think that censorship (including through demonetizing publications) makes the problem go away—in fact, it makes it worse.”

In the latest, and somewhat confusing twist, Substack now says it has removed “some publications” but hasn’t changed its underlying rules. In a statement to Platformer, Substack’s founders said that an investigation “found that five out of the six publications you reported do indeed violate our existing content guidelines, which prohibit incitements to violence based on protected classes.” The founders said they were working on new moderation tools “so Substack users can set and refine the terms of their own experience on the platform.”

A Substack spokesperson also confirmed to Engadget that the company had removed “some” newsletters, though it wasn’t clear if the company had removed any others besides the ones reported by Platformer. "Substack regularly reviews reports of all potential content violations," the spokesperson said. “Substack did not change its policies."

Meanwhile, some prominent newsletter writers have already left the platform in protest and have reported cancellations among their paid subscribers. And it's unclear whether the company's latest act of moderation will be enough to reassure its critics. As Casey Newton, who runs Platformer noted, “this issue has raised concerns that go beyond the small group of publications that violate the company’s existing policy guidelines.”