Focusing on Mexican cartels and affiliated drug trafficking organizations, this article examines how self-proclaimed cartel members use social media to further the criminal activities of their organizations. Employing an opensource, intelligence-driven methodology, the authors identified, followed, and mapped the connections between and among 75 alleged cartel members over a period of 4 months. Results indicated that cartel members actively use Facebook to plan, organize, and communicate in real-time. These findings provide tentative validation to the utility of using open-source social media platforms to study the social structure and operations of Mexican drug cartels. Implications for law enforcement, homeland security, and the intelligence enterprise are discussed.