Cornell Law professor Michael C. Dorf discusses a lawsuit in which the government of Mexico is suing U.S. firearms manufacturers in federal court for failing to take reasonable steps to prevent their weapons from ending up in Mexico, profit from the trafficking of U.S.-made guns to Mexico, and in some respects deliberately target the illegal Mexican market. Professor Dorf argues that while the lawsuit presents strong moral and policy grounds for granting the Mexican government the relief it seeks, a 2005 federal statute, the Protection of Lawful Commerce in Arms Act (PLCAA), will likely prevent it from succeeding.