CHALLENGING TRUTH AND TRUST: SOCIAL MEDIA AND DEMOCRACY Many people are questioning whether social media platforms are threatening democracy. Concentrated in just a few hands, large datasets about public and private life—including data on demographics and public attitudes and opinion—are valuable assets to lobbyists seeking to pass legislation, foreign governments interested in controlling domestic conversations, and political campaign managers working to win an election. While the Internet has certainly opened new avenues for civic participation in political processes—inspiring hopes of a democratic reinvigoration—the parallel rise of big data analytics, “black-box” algorithms, and computational propaganda, are raising significant concerns for policymakers worldwide. In many countries around the world, divisive social media campaigns have heightened ethnic tensions, revived nationalistic movements, intensified political conflict, and even resulted in political crises—while simultaneously weakening public trust in journalism, democratic institutions, and electoral outcomes. “Cyber troops” are defined here as government or political party actors tasked with manipulating public opinion online (Bradshaw & Howard, 2017). Specifically, we focus on how these actors disseminate computational propaganda over social media platforms. We define computational propaganda as the use of automation, algorithms and big-data analytics to manipulate public life (Howard & Woolley, 2016). The term encompasses issues to do with socalled “fake news”, the spread of misinformation on social media platforms, illegal data harvesting and micro-profiling, the exploitation of social media platforms for foreign influence operations, the amplification of hate speech or harmful content through fake accounts or political bots, and clickbait content for optimized social media consumption. This report examines how governmental cyber troops make use of computational propaganda to shape public opinion. The affordances of social media platforms make them powerful infrastructures for spreading computational propaganda (Bradshaw & Howard, 2018). Social media are particularly effective at directly reaching large numbers of people, while simultaneously micro-targeting individuals with personalized messages. Indeed, this effective impression management—and fine-grained control over who receives which messages—is what makes social media platforms so attractive to advertisers, but also to political operatives and foreign adversaries. Where government control over Internet content has traditionally relied on blunt instruments to block or filter the free flow of information, powerful political actors are now turning to computational propaganda to shape public discourse and nudge public opinion. 4