This paper traces the role of ideology in shaping the beliefs and situated knowledge used by information technology and security managers to make sense of and justify systems of surveillance they oversee. In particular, the analysis explores the role of the contested meanings of the ideology of ‘freedom’ as an important resource in this process of meaning construction, providing a ground-level account of the process of interpellation, described by Louis Althusser as the subjectification of individuals by ideology made available from dominant discourse.