The increasing dependence of modern societies, industries, and individuals on information technology and computer networks renders them ever more vulnerable to attacks on critical IT infrastructures. While the societal threat posed by hackers and other types of cyber-criminals has been growing significantly in the last decade, main-stream criminology has only recently begun to realize the significance of this threat. Cyber-criminology is slowly emerging as a subfield of criminological study and has yet to overcome many of the problems other areas of criminological research have already mastered. Aside from substantial methodological and theoretical problems, cyber-criminology currently also suffers from the scarcity of available data. As a result, scientific answers to crucial questions, such as who exactly the attackers are and why they engage in hacking activities, remain largely fragmentary. The present study begins to fill this remaining gap in the literature. It examines survey data about hackers, their involvement in hacking, their motivations to hack, and their hacking careers. The data for this study was collected during a large hacking convention in Washington D.C. in February 2008. The theoretical framework guiding the analyses is the rational choice perspective (Clarke & Cornish, 1985). Several hypotheses about hackers are derived from the theory and some of its models are transposed into the context of hackers. Results suggest that the rational choice perspective is a viable theory when applied to cyber-criminals. Findings also demonstrate that the creation of more effective countermeasures requires adjustments to our understanding of who hackers really are and why they hack.