This research investigated the intergroup properties of hostile ‘flaming’ behaviour in computer-mediated communication and how flaming language is affected by Internet identifiability, or identifiability by name and e-mail address/geographical location as is common to Internet communication. According to the Social Identity Model of Deindividuation Effects (SIDE; e.g. Reicher, Spears, & Postmes, 1995) there may be strategic reasons for identifiable groups members to act in a more group-normative manner in the presence of an audience, to gain acceptance from the in-group, to avoid punishment from the out-group, or to assert their identity to the out-group. For these reasons, it was predicted that communicators would produce more stereotype-consistent (group-normative) descriptions of out-group members' behaviours when their descriptions were identifiable to an audience. In one archival and three experimental studies, it was found that identifiability to an in-group audience was associated with higher levels of stereotype-consistent language when communicators described anonymous out-group targets. These results extend SIDE and suggest the importance of an in-group audience for the expression of stereotypical views.