In the 19th century, to protect private property, the legislator sometimes had to be wary of dishonest owners. Faced with the resurgence of certain financial crimes, swindles and other frauds, legislative policy oscillated between rigorous repression, intended as a deterrent but deemed excessive, and more flexible sentencing, to make criminal law more effective. The legislator’s main concern was to define the contours of the criminal figures that were developing as a result of the century’s economic and social changes. Among these, two stand out: the insurance swindler, an owner who sets fire to his own property in order to defraud his insurer, and the fraudulent banker, who makes undue profit from mismanagement. In trying to catch them, French law tries, with varying degrees of success, to meet society’s need to identify and punish criminal scams fairly.