In this study, we seek to understand what stimulates retaliatory behaviors in online peer-to-peer environments. We use Deindividuation Theory, Cognitive Appraisal Theory, and the dark triad of personality traits to understand how retaliatory responses stem from combinations of environmental, social, and psychological factors. We use these insights to propose that people are more likely to respond to abrupt criticism with retaliation in online, peer-to-peer environments. Furthermore, we posit that individuals with strong dark triad personality characteristics are more likely to engage in retaliatory behaviors. We test these hypotheses using an experiment designed around a peer-to-peer grading system. Our results suggest people retaliate more frequently in online environments if the criticism they receive is unexpected; furthermore, we find people high in dark triad traits are even more likely to engage in retaliation under these conditions.