For years, Twitter, like other social media platforms, has freely given its platform data to independent researchers so that they can analyze everything from online trolling to the spread of misinformation. Those studies have been critical to understanding the tactics used by scammers, foreign influence campaigns and other malicious actors trying to manipulate social media.

But now researchers fear the future of that work is under threat, after Twitter abruptly announced plans last week to restrict access to this data and charge money for it.