When I was about 12 years old, my father introduced me to the fine art of numismatics, otherwise known as coin collecting, by giving me a Whitman Roosevelt Dime collectors book. He probably intended that I have a backup plan in case the court I spent most of my time in then—the basketball court—did not work out for me. In order to fill the book’s empty dime slots, you had to get all dimes minted from 1946 through 1964. It was no easy feat. It required regular visits to the local bank branch, waiting in long lines, and exchanging hard earned dollar bills for five dollar rolls of dimes. Then followed the arduous task of cleaning and scrutinizing the coins at home for the special minted markings that would identify that small silver nugget as a thing that was worth more than its face value. That was my pre-Internet world of “currency transactions.” Today, we have digital currencies that are not limited by country or continent, and that may be traded online in “digital wallets,” as referenced in United States v. Ulbricht, 2017 U.S. App. LEXIS 9517 (May 31, 2017).

Last month in Ulbricht, the U.S. Court of Appeals for the Second Circuit upheld the legality of evidence obtained as a result of court-ordered pen registers that federal agents obtained for defendant’s Internet routing data. The evidence provided a key link connecting defendant’s online activity to a massive narco-money laundering Bitcoin criminal enterprise scheme that thrived through a website he created called Silk Road.