A three-condition (rejection, criticism, control) single-factor experiment (N = 78) reveals that even relatively minor face-threatening acts of rejection or criticism on a social-networking site similar to Facebook lead to increases in self-reported negative affect and retaliatory aggression, compared with a control. A mediation model demonstrates that face-threatening acts lead to direct effects on negative affect and an indirect affect on retaliatory aggression through negative affect. Findings are discussed in relations to face theory and politeness theory.