In a letter to Facebook CEO, Mark Zuckerberg, 51 organizations and 29 individuals, including CFA, urged the social media giant to withdraw a cease & desist letter sent to New York University (NYU). Facebook directed NYU to shutdown their Ad Observer browser plugin, a tool that allows Facebook users to volunteer to contribute information about the ads and ad targeting they encounter on the platform. The groups state that the plugin has allowed researchers and journalists to learn about Facebook’s advertising practices and has revealed serious flaws in Facebook’s advertising transparency policies.