TikTok gave teens and children access to a placebo safety feature instead of a real one that would have let them refresh their recommendations in an experiment, according to allegations in New York’s lawsuit against the social media platform.

Reuters reports that TikTok’s experiments involved thousands of users, including teens and children, who had opted to use safety features like “Algo Refresh,” a tool that allows users to reset their recommendations and stop seeing unwanted or potentially harmful content.

Although the users believed that they had activated the feature, their feeds didn’t change, unlike those of users who weren’t part of the experiment and had access to a fully functioning version of the tool.

New York’s lawsuit against the company is one of more than two dozen cases brought by states that accuse the social media giant of designing its platform to encourage addictive use among children and misleading users about its safety.

“We continuously make improvements to our platform which means that, like most companies, we regularly test new products and features to validate the ​experience and understand how they work in the real world,” TikTok told told Reuters.

TikTok did not immediately return a request for comment.

The lawsuit also claims that TikTok conducted other experiments. Bloomberg reported in June that one such experiment withheld a safety feature from 15 million U.S. users, including a teenager who later died by suicide.