How much bitcoin the U.S. government has hoarded.

When Alexandre Cazes hanged himself in a Thai jail cell in July, the 25-year-old left behind the trappings of a big-league drug dealer: villas, Lamborghinis, a Porsche, bank accounts in Liechtenstein and Switzerland. But Cazes, who authorities allege operated AlphaBay, the world’s largest black-market website for drugs and weapons, also left something else: Internet “wallets” holding millions of dollars’ worth of Bitcoin and other virtual currencies.
Cazes’s digital loot is now property of the U.S. Justice Department, which seized it during a global sting operation. The agency plans to sell it, and given that Bitcoin’s value has soared more than fivefold since then, it could reap a huge windfall. But if you want to find out who’s holding those coins, or when they’re being sold, you’ll need extensive cybersleuthing skills—and a lot of free time.
These digital seizures and sales, unheard-of five years ago, are fast becoming routine. Bitcoin’s enduring popularity among online wrongdoers, and its growing presence in criminal busts, has turned Uncle Sam into a major player in cryptocurrency markets. While exact figures are impossible to pin down, documentary evidence and interviews with current and former defense attorneys and prosecutors suggest that at least $1 billion worth of digital coins, and possibly much more, has spent time in the custody of U.S. law enforcement.
But once in government hands, this digital hoard disappears behind a cloak of secrecy. The anonymity that makes Bitcoin a darling of libertarians—along with opaque property-seizure laws hated by those same libertarians—makes it virtually impossible for the public to follow the digital money. And as federal agencies have been drawn into an ever-growing role in the cryptocurrency boom, their efforts to guard their digital gold have led to surprises, stumbles, and sometimes sin.
The U.S. Marshals Service is the oldest law-enforcement agency in the country, counting gunslingers like Wyatt Earp and Wild Bill Hickok among its alumni. More recently, TV and movies have familiarized many Americans with its role transporting prisoners and tracking dangerous fugitives. Far fewer people know the marshals sell Bitcoin.
A decades-old law gives the Marshals Service, which is part of the Department of Justice, primary responsibility for disposing of items seized by other federal law-enforcement agencies. That’s why you can visit the marshals’ website and ogle boats, cars, planes, wristwatches, and other ill-gotten gains snatched by the FBI and other agencies, all available at public auction. The seizure process, known as forfeiture (see sidebar), became more commonplace and controversial in the 1980s after Congress made it easier for federal officials to sell assets tied to drug crimes.
At the time, no one knew these assets would someday include money mined on computers. That changed earlier this decade during an epic investigation into Silk Road—a global eBay for illegal drugs. A young Texan known as Dread Pirate Roberts (real name: Ross Ulbricht) built Silk Road on three then-new technologies: cheap cloud data storage; the Tor browser, which let people roam dark parts of the Internet undetected; and Bitcoin, which let them pay each other in a secure, semi-anonymous manner, without involving banks.