This article examines the circumstances under which civilians, using protests as a mechanism, alter the strategic use of violence by armed actors (rebels and state forces). By examining the civil war in Colombia between 1988 and 2005, this study finds that combatants decrease their attacks against the population when civilians protest against the enemy. Combatants interpret such demonstrations as costly signals of loyalty. Furthermore, when insurgents are the target of the protests, insurgents increase repression against civilians as rebels get stronger. In contrast, state forces (and paramilitaries) compensate for their weakness in the area by multiplying civilian victims. Both state forces and rebels, however, are likely to decrease violence against civilians when civilians protest against both parties in contested zones. In such contexts, armed actors are likely to refrain from retaliation because any violence might drive noncombatants toward the enemy.