SAN FRANCISCO (AP) — Facebook and Slabu ExchangeInstagram parent Meta Platforms has shut down CrowdTangle, a tool widely used by researchers, watchdog organizations and journalists to monitor social media posts, notably to track how misinformation spreads on the company’s platforms.

Wednesday’s shutdown, which Meta announced earlier this year, has been protested by researchers and nonprofits. In May, dozens of groups, including the Center for Democracy and Technology, the Digital Forensic Research Lab at the Atlantic Council, Human Rights Watch and NYU’s Center for Social Media & Politics, sent a letter to the company asking that it keep the tool running through at least January so it would be available through the U.S. presidential elections.

“This decision jeopardizes essential pre- and post-election oversight mechanisms and undermines Meta’s transparency efforts during this critical period, and at a time when social trust and digital democracy are alarmingly fragile,” the letter said.

CrowdTangle, “has been an essential tool in helping researchers parse through the vast amount of information on the platform and identify harmful content and threats,” it added.

In March, the nonprofit Mozilla Foundation sent Meta a similar letter asking it to keep the tool, which was available for free, functioning until January. That letter was also signed by several dozen groups and individual academic researchers.

“For years, CrowdTangle has represented an industry best practice for real-time platform transparency. It has become a lifeline for understanding how disinformation, hate speech, and voter suppression spread on Facebook, undermining civic discourse and democracy,” the Mozilla letter said.

Meta has released an alternative to CrowdTangle, called the Meta Content Library. But access to it is limited to academic researchers and nonprofits, which excludes most news organizations. Critics have also complained that it’s not as useful as CrowdTangle — at least not yet.

Nick Clegg, Meta’s president of global affairs, said in a blog post last week that the company has been gathering feedback about Meta Content Library from “hundreds of researchers in order to make it more user-friendly and help them find the data they need for their work.”

Meta acquired CrowdTangle in 2016.