This Note analyzes the effects of Bitcoin and analogous virtual currencies on anti–money laundering (AML) enforcement. Part I gives a brief primer on money laundering and virtual currencies. Part II offers a Bitcoin primer, which differentiates Bitcoin technology from traditional currencies and competing virtual currencies. Part III analyzes whether Bitcoin is legal to use or trade in the United States, using domestic and international adoption of Bitcoin for guidance. Part IV discusses whether current U.S. AML regulatory schemes encompass the entirety of Bitcoin use, finding that it does not. Finally, Part V offers suggestions for a regulatory scheme encompassing Bitcoin and analogous virtual currency technologies. Ultimately, this Note recommends regulating Bitcoin currency exchanges under existing AML regulation schemes instead of broadening statutory definitions to control all aspects of Bitcoin or analogous virtual currencies.