Why possible loss of CrowdTangle worries fact-checkers and disinformation researchers

How do you know if the fact-checking program works? The fact-check group Science Feedback attempted to answer this question by analyzing Facebook data captured through CrowdTangle and Buzzsumo. (…) “In our research we have been able to show how much Facebook is reducing the visibility of posts in these repeat offender accounts. We were able to transparently verify that Facebook is implementing this policy. Otherwise there is no way of knowing that. We really need this kind of data if we want to be able to measure what is happening on the platform,” Vincent told Rappler.