Recent literature analyzes the use of social media by terrorist organizations, gangs, and other criminal groups. Despite the valuable insight that this approach provides on these actors, the use of social media by Mexican drug trafficking organizations (DTOs) remains largely understudied. This study provides information on the scope and nature of Mexican DTOs’ online presence, a demographic snapshot of their users, and insight into the internal dynamics of these organizations through the systematic study of primary-source data collected from 150 Facebook accounts likely to belong to members of Mexican DTOs. This information gleaned from social media has the potential to enrich our knowledge and understanding of these organizations and to serve as a guide for more effective and assertive anti-narcotics policies and strategies in Mexico and Latin America. Finally, this study raises new questions and provides avenues for future research on specific issues and trends related to DTOs observed throughout the analysis. This article is available in Journal of Strategic Security: http://scholarcommons.usf.edu/jss/vol9/iss3/5