Research has shown that group support systems (GSS) can be used to substantially improve learning at all levels of formal education. However, some instructors are reluctant to adopt GSS because they are concerned that learners will engage in flaming, or verbal attacks intended to offend either persons or organizations and often characterized by profanity, obscenity, and insults. This paper posits that flaming is caused by hostility engendered by a perception that vested interests have been or are about to be violated. It further posits that the relationship between hostility and flaming is moderated by personal values and risk of reprisal. A longitudinal experiment is presented that provides empirical support for the model. The paper then reports five field cases highlighting various strategies used by instructors for reducing or eliminating flaming.