With openness comes vulnerability. David Sloss’s new work, Tyrants on Twitter, elevates the abuse of social media by autocrats to a new war front, reminiscent of the concerns for foreign penetration during the Cold War. His response to this new round of “information warfare” is the mobilization of a transnational alliance of the 40 or so leading democratic countries to register citizens for use of social media and filter out tyrants and their fronts, be they real people or bots. The book begins by chronicling the extent of democratic decline, a well-defended starting point. More complicated is the argument that the correlation between democratic decline and foreign interference establishes the causal role of the latter. Even more difficult is the conclusion that there is need for war-like footing to mobilize against foreign threats. The review ends with a note of caution on the costs associated with democratic societies closing up in the face of foreign challenge.