Social media has enabled identity theft, targeted advertising, psychometric profiling, dissemination through bots and the creation of false personas. The same psychology that explains why social media is so credible and addictive also explains why social media platforms such as YouTube, Facebook, Instagram and Twitter are vulnerable to attack. As a case in point, Russia’s Internet Research Agency launched the “translator project” which hacked voter registration data, stole the identities of thousands of American citizens, and posed as interest groups and political activists. The result, says the author, is the most effective influence campaign in world history.