Structural violence is violence that is permissible, even encouraged. It refers to the invisible social machinery of inequality that reproduces social relations of exclusion and marginalization via ideologies, stigmas, and dangerous discourses (such as "youth violence" itself) attendant to race, class, sex, and other invidious distinctions. Structural violence "naturalizes" poverty, sickness, hunger, and premature death, erasing their social and political origins so that they are taken for granted and no one is held accountable except the poor themselves. Structural violence also refers to the ease with which humans are capable of reducing the socially vulnerable (even those from their own class and community) into expendable non-persons, thus allowing the licence--even the duty--to kill them. I exemplify this through two ethnographic critical case studies: the operation of a virulent death squad in Northeast Brazil that mobilized the support of ordinary people in an almost genocidal attack against Afro-Brazilian street kids and young "marginals"; and the uneasy truce with, and incomplete integration of "dangerous and endangered" youth still living in squatter camps and shack communities of urban South Africa.