Two studies were conducted to investigate the role of social identity in appraisals of the purpose and acceptance of surveillance. In Study 1 (N ¼ 112), a survey study demonstrated that there is a negative relationship between identification with one's city and the extent to which public closed circuit television (CCTV) surveillance is perceived as an invasion of privacy. This relationship was mediated by perceptions that the purpose of surveillance is to ensure safety. Study 2 (N ¼ 139) manipulated identity salience at the sub-group and superordinate level and the source of surveillance. Results demonstrated that surveillance originating from fellow sub-group members was perceived as less privacy invading than surveillance originating from the superordinate group, but only when that sub-group identity was salient. No differences in perceptions of privacy invasion were found when the more inclusive identity was made salient. We argue that whether surveillance is perceived as an invasion of privacy depends on the perceived social relationship with the source of the surveillance-surveillance is perceived as more acceptable when it originates from a group with which one identifies or shares an identity. Practical implications are discussed. Copyright # 2009 John Wiley & Sons, Ltd.You had to live-did live, from habit that became instinct-in the assumption that every sound you made was overheard, and except in darkness, every movement scrutinised'. George Orwell, Nineteen Eighty-Four (1949, p. 7).While surveillance is clearly not at the level portrayed in Nineteen Eighty-Four, with 'Big Brother' appearing on the television, rather than watching through the telescreen, levels of surveillance are at an extremely high level in modern society. For example, BBC News (2002) reported that the average UK citizen is captured on closed circuit television (CCTV) 300 times per day (see also Armitage, 2002;Short & Ditton, 1998). Much research into surveillance has focussed on its intended outcomes and assesses, for instance, the effectiveness of surveillance systems in deterring crime or in promoting productivity at work (e.g. D' Urso, 2005Urso, , 2006Welsh & Farrington, 2003). Implicit in such research, we would argue, is the notion that people will be more accepting of surveillance if it is effective in achieving those goals. However, such a focus neglects the fact that people may be concerned about the use of surveillance for other reasons too: Many feel it implies a lack of trust, infringing privacy and civil liberties in both the workplace (Lee & Brand, 2005;Whitty & Carr, 2006) and in public spaces (Honess & Charman, 1992).In the present research, we depart from previous psychological analyses of surveillance, in that we suggest surveillance is not simply seen as good or bad, but that its perception may be affected by additional factors. For example, D'Urso (2006) suggests that the direct relationship between increased surveillance levels and various negative outcomes such as reduced European Journal of Social Psy...