Major social media platforms increasingly serve as information gatekeepers, putting awesome power in the hands of tech giants with little oversight. These companies – like Facebook, Google, Twitter – were not fundamentally designed to serve the public good, but to generate growth and profits. Their surveillance-advertising business model relies on harvesting and monetizing data, so they developed products and algorithms to maximize engagement. Those algorithms inherently reward outrageous content, reinforce biases irrespective of truth, and filter like-minded individuals into small echo chambers. Moreover, bad actors are weaponizing these data-rich platforms to manipulate users – be it to suppress voters, prey on consumers, or promote extremism. Democracy requires a shared baseline of facts. But this online information landscape is instead creating a toxic patchwork of personalized pseudo-realities. Social media companies face an undeniably challenging task in self-regulating. But they can and must do more to mitigate harms and promote the greater good.