In two studies we investigate how level of surveillance moderates followers' responses to leaders with whom they either do or do not share identity. Study 1 (N ¼ 80) demonstrated that imposing high surveillance where identity is shared with a leader undermined perceptions of the leader as a team member, reducing levels to that of leaders without a shared identity. Study 2 (N ¼ 84) replicated this finding, also demonstrating that willingness to work for the group declined when leaders with shared identity used high surveillance (compared to a low surveillance condition). This process was partially explained by perceptions that surveillance was an invasion of privacy. Together, these studies illustrate that the benefits of shared identity are easily undermined when a leader uses surveillance in a context where it is unnecessary. Copyright # 2009 John Wiley & Sons, Ltd.'. . .the perfection of power should tend to render its actual exercise unnecessary. . .' Foucault, Discipline and Punish: The Birth of the Prison (1977, p. 201). 'The perfection of power', as Foucault describes it refers to a power so absolute that it need not be exercised. Such complete control could arise from the omnipresence of power afforded by the extensive use of surveillance, or from genuine influence, whereby individuals are inspired to comply without the need for coercion. Indeed, there are a number of ways in which a leader may influence his or her followers (Bass, 1985; Haslam, 2004;Reynolds & Platow, 2003;Simon & Oakes, 2006;Turner, 2005). A leader may utilize the power inherent in any leadership position, by enforcing rules and ensuring such rules are followed by the use of monitoring and surveillance. In contrast, a leader may benefit from common ground, as a shared sense of identity motivates followers to cooperate to achieve a joint goal.In the present research, we investigate the way in which these two types of power interact. Importantly, we argue that these two forms of leadership-realized through the enforcement of power via surveillance, or through influence afforded by a shared identity-do not necessarily sit well together. Although a shared social identity may influence followers to accept surveillance from their leaders, leaders who attempt to use both types of power simultaneously, to maximize effectiveness, may well experience resistance from followers rather than cooperation. In particular, if leaders who share an identity with their followers impose surveillance, they may experience negative repercussions because, by using surveillance, they may create the impression that identity is not shared after all. That is, the mere perception of shared European Journal of Social Psychology Eur. J. Soc. Psychol. 40, 1046-1061 (2010 identity with a group leader-that this person is 'one of us'-gives the leader a licence to act on behalf of the group and enhances the leader's capacity to influence and lead. Any act that damages this perception may break the 'one of us' perception and thereby forms a fertile ground for followe...