This paper examines a relatively new trend: market-based crime prevention. The insurance firm is an exemplary agent of this new type of crime prevention. Although the traditional focus of insurance has been on losses sustained after a crime or other catastrophe, we explore the shift from reactive to proactive crime management by the insurance industry. This trend is part of a more general decentralization of policing, from state-controlled agents to community- and market-based third parties. New ideologies support these shifts, including an actuarial logic about crime and a view of the prudent person.