Sex-trafficking fugitive Michael Pratt vanished for 3 years — until a data leak led to his capture. The leak involved cryptocurrency "wallets" he used to secure his bitcoin passwords. The leak revealed he'd shipped one to a Mailboxes Etc.

in Barcelona, a clue that cracked the case. Four days before Christmas in 2022, Michael James Pratt — a New Zealander accused of running the most prolific sex-trafficking ring in US history, with at least 400 young victims — was thrown to the floor of his Madrid hotel room and handcuffed by Spanish police. As Pratt awaits trial in a Southern California jail, facing a possible life sentence, little has been revealed about how police located and captured him after three years on the run.

But video of his arrest, tweeted afterward by Spain's Policia Nacional, shows the precise instruments of his undoing: four gunmetal-silver cryptocurrency flash drives. The four pieces of hardware held the passwords for $500,000 in bitcoin that federal prosecutors say he earned during his decade of running the notorious Girls Do Porn trafficking ring. Here is the story of Michael Pratt, the Girls Do Porn ring, and how a team of civilian supersleuths followed a twisty trail that began with these pocket-sized crypto hard drives and ended on that hotel room floor.

Here, too, is a story of justice. Last month, federal prosecutors said that the trafficking proceeds they seek to recover include the bitcoins protected by those four hard drives. The money would b.