Social media platforms have come to define the modern digital world — and the real world it's meant to represent. We turn to these platforms for news, to interact with elected officials, to catch up with friends and to converse with the greater world beyond our own. Yet these platforms are not neutral forums. They actively intervene to remove speech with which they disagree. Increasingly, they also turn to a small number of fact-checking websites to arbitrate what constitutes "truth," placing a small number of people in charge of, essentially, defining reality.