That may sound like a paradox. Bitcoin is the world’s most popular digital currency, and it’s controlled by a vast collection of computers spread across the internet. But TradeFortress knows what he’s talking about. He’s the founder of a inputs.io, a company that used to store bitcoins in digital wallets for people across the globe. The site was just hacked, with the bandits making off with more than a million dollars’ worth of bitcoins.