This leaves the biggest source of private power over free speech: social media. Facebook and Twitter function as key venues for political debate. And yet they frequently ban users on arbitrary grounds. They have also prohibited the expression of controversial points of view about matters of intense public interest. And while they have justified these measures with the noble goal of fighting “misinformation,” the concept is defined so nebulously that they have, in practice, ended up taking sides in highly important and complex public debates.
