Although employee computer abuse is a costly and significant problem for firms, the existing academic literature regarding this issue is limited. To address this gap, we apply a multi‐theoretical model to explain employees' intentions to abuse computers. To understand the motives for such behaviour, we investigate the role of two forms of organizational justice – distributive and procedural – both of which provide explanations of how perceptions of unfairness are created in the organizational context. By applying deterrence theory, we also examine the extent to which formal sanctions influence and moderate the intentions to abuse computers. Finally, we examine how the potential motives for abuse may be moderated by techniques of neutralization, which allow offenders to justify their actions and absolve themselves of any associated feelings of guilt and shame. Utilizing the scenario‐based factorial survey method for our experimental design, we empirically evaluated the association between these antecedents and the behavioural intention to violate Information systems (IS) security policies in an environment where the measurement of actual behaviour would be impossible. Our findings suggest that individual employees may form intentions to commit computer abuse if they perceive the presence of procedural injustice and that techniques of neutralization and certainty of sanctions moderate this influence. The implications of these findings for research and practice are presented. © 2016 John Wiley & Sons Ltd