Legitimate companies occasionally find themselves doing business with criminals, wittingly or unwittingly. Past decades have witnessed a dramatic expansion in the array of criminal law and regulatory rules that govern such entanglements. These rules raise fundamental questions about commerce and society, such as: when can someone be excluded from day-to-day commercial interactions? Where is the boundary between legitimate surveillance of suspicious transactions and financial privacy? And, ultimately, what is the point of financial crime rules: are they meant to exclude suspected criminals from the legitimate economy, or help to gather intelligence on them? This book is the first comprehensive account of how these dilemmas shape financial crime rules. Based on a sweeping overview of international experience, it tells a story that will be of interest to a wide audience ranging from the seasoned financial crime expert to the general reader.