The Russian operatives accused of hacking the Democratic National Committee in 2016 didn’t use cash or credit cards. To pay for servers and domain names, they turned to Bitcoin, a digital currency that allows for secure payments without banks, government authorization or verified identities.

Yet what makes Bitcoin and other cryptocurrencies appealing to criminals also limits their usefulness to them. Bitcoin transaction records helped investigators find the Russian agents under indictment. To cover their tracks, the perpetrators of the hacking scheme would have been better off using briefcases full of cash.

The details of this case are an encouraging sign. Cryptocurrencies are part of a global experiment in making money — the secure exchange of value — as decentralized as information on the internet. Just as anyone can put up a blog without going through traditional media, cryptocurrencies can remove control from financial intermediaries.