"It is becoming increasingly apparent that fundamental principles underlying democracy—trust, informed dialogue, a shared sense of reality, mutual consent, and participation—are being put to the test by certain features and attributes of social media. As technology companies increasingly achieve financial success by monetizing public attention, it is worth examining some of the key issues and unintended consequences arising as a result. Six key issues: Echo chambers, polarization, and hyper-partisanship [...]; Spread of false and/or misleading information [...]; Conversion of popularity into legitimacy [...]; Manipulation by “populist” leaders, governments, and fringe actors [...]; Personal data capture and targeted messaging/advertising [...]; Disruption of the public square [...]" (Executive summary)