This paper reports the results of an experiment where anonymous and identified comment groups discussed five ethical issues via computer-mediated communication (CMC). The results suggest that comment anonymity leads to more participation and less change in opinion than comment identification, while equality of participation and post-discussion agreement do not differ. Further analysis of the change in opinion found that anonymity increases the number of arguments that are expressed during a discussion; however, other group members seem to be less persuaded under conditions of anonymity in spite of the larger set of arguments expressed. Anonymity also led to more arguments in support of questionable behavior, suggesting that the freeing effects of anonymity apply to the social desirability of arguments and opinions, but may not encourage group members to participate in discussions.