In terms of opportunity, the literature on this subject has a balance of focus on two areas. The first examines how opportunities may arise through the absence and poor implementation of security controls. The second area of the literature relates to how changes in organizational structure and environments increase opportunities for crime. The author identifies deficiencies in existing notions of "opportunity," arguing that opportunities for crime arise in and as a consequence of the daily workings of an organization. Consequently, any approach used to understand opportunity must be able to address those elements involved in these daily workings and also explain how interactions between them may create opportunities. The paper then proceeds to explain how situational crime prevention (SCP) is suited to reducing opportunities for security breaches. SCP measures involve the design, management, or manipulation of the environment with the threefold aim of increasing the risk and effort for crime while reducing the rewards. The author then discusses how environmental criminology, the rational-choice perspective, and lifestyle and routine-activity theories of crime causes are addressed by SCP. Suggestions are then offered for a strategy to counter computer-related crime with SCP measures. 2 figures and 42 references