Lecture, three hours. Influence of social media on public discourse and public policy, in U.S. and overseas, has been far-reaching and dramatic. Exploration of positive and negative impacts of social media on individuals and society. Topics include tension between free expression and censorship; and public policy implications and responses (or lack thereof) to use of social media as platform for disseminating fake news, conspiracy theories, white nationalism, racism, and violence. Consideration of whether government should impose content rules on social media companies (as Federal Communications Commission does for broadcast media), or whether corporate terms and conditions of service as self-regulatory model should be relied on. Exploration of how to measure relative impact of social media versus money/campaign contributions on current U.S. political system. Letter grading.