Chapter 9 discusses the Mexican government’s 2021 lawsuit in Massachusetts federal court against seven American gun manufacturers to recover the costs to the Mexican government because of gun violence in Mexico. The chapter sets forth statistics documenting the escalating incidence of gun violence in Mexico, attributable to the illegal gun trafficking from the United States and used by Mexican drug cartels against Mexican citizens. The narrative focuses on the American border states and gun defendants responsible for the flood of guns into Mexico. The chapter discusses Mexico’s basis for its lawsuit, and the claims alleged sounding in tort theories of negligence, negligence per se, and public nuisance. This discussion details the defendants’ responses and the district court’s dismissal of the lawsuit, based on PLCAA immunity. The court examined the question of the extraterritorial application of PLCAA to events occurring outside the United States. On appeal, the First Circuit Court reversed the district court’s dismissal, holding that PLCAA did have extraterritorial application but that a PLCAA exception permitted Mexico’s lawsuit to proceed. The chapter ends with a discussion of the pending certiorari petition to the U.S. Supreme Court by Smith & Wesson.