The circumvention of technical protection systems and the making of tools to enable such circumventions may seem to financial cryptographers a wholly natural and constructive set of activities. This community knows that it is impossible to make encryption systems more secure unless one tests how strong they are from time to time by trying to break them. However, now that other industries, notably entertainment industries, are relying on encryption technologies to protect information in digital form, it should not be surprising that these industries have a different perspective about circumvention and circumvention technologies. Copyright industry spokesmen are fond of likening the act of circumventing a technical protection system to “breaking and entering” a dwelling; they also liken the tools built to enable circumvention to “burglars’ tools,” the possession or sale of which has been outlawed in numerous states. The Digital Millennium Copyright Act (DMCA) anticircumvention regulations, enacted by the U.S. Congress in October 1998, on which this paper will mainly focus, address the concerns of these industries that circumvention of technical protection systems substantially threatens the viability of copyright industries such that both the act of circumvention and the making of circumvention-enabling technologies need to be heavily regulated.