The Guerreros Buscadores and dozens of other groups in Mexico scour the country for people who are missing. More than 130,000 people have been reported missing since 2006, according to official records. It is perilous work in a perilous environment. Mexico is neither at war nor under a military dictatorship, yet thousands of people disappear every year amid cartel violence. Clandestine graves are discovered on a semiregular basis; more than 70,000 unidentified remains have piled up in morgues and cemeteries.