Back in 2013, when you could still mine bitcoins at home, WIRED was sent a small, sleek mining device manufactured by the now-defunct Butterfly Labs. We turned on the Roku-looking machine in our San Francisco offices and allowed it to do its job. A small fortune was soon amassed, now worth around $100,000. Then, we lost the money. Forever.

Here's what happened to WIRED's 13 Bitcoins—and to the millions of others that have faced the same fate.

Stefan Antonowicz, WIRED's then-head of engineering, set up the miner. Robert McMillan, a former senior writer for WIRED (who now works at The Wall Street Journal), then wrote about it. "When we received that Butterfly miner, we had a new ethical question: What do you do with the proceeds of a review device that essentially prints money?" says McMillan.

First, it's probably worth explaining how WIRED accrued its six-figure Bitcoin fortune. While fiat currencies, like the dollar, rely on banks and government regulators, Bitcoin runs on a peer-to-peer network monitored by an army of volunteer miners that run specialized software. Every 10 minutes, all the miners in the network race to solve a series of complex cryptographic math problems. The computers that win are awarded a slice of 12.5 new bitcoins. (That number halves every four years; it was 25 when we got our miner.) Usually, the fastest computers in the network solve the problems first.

Over time, the puzzles have gotten harder, leading to a kind of computing-power arms race. Back when Bitcoin first launched, it was possible to mine coins using an everyday computer. These days, you'll need specialized hardware significantly more powerful than the Butterfly Labs miner WIRED had. Currently, there are about 17 million bitcoins in existence; by the year 2140, all 21 million planned Bitcoins will have been mined. You can learn more about the process in our Guide to Bitcoin.)

WIRED's miner essentially won the Bitcoin math lottery a couple of times, allowing it to generate a little over 13 coins into the network. Then, the staff had to figure out what to do with them. "We had a very long conversation, over several weeks, about what to do with the money," says Michael Calore, a senior editor at WIRED who has been at the magazine since 2006. Some staff members argued the Bitcoin should be donated, or set aside for a charitable purpose in the future. Others said it had to be destroyed permanently. What was agreed upon was that the money shouldn't just sit there, because it could influence how the magazine reported on cryptocurrencies.

"I said we had to dump it and donate the money to charity soonest or we wouldn't be able to cover Bitcoin," says Adam Rogers, a deputy editor at WIRED. "We had to disclose it in every story." Eventually, it was decided that the private key, which unlocks the Bitcoin wallet and allows the funds to be spent, should be destroyed.

"We talked about donating it to a journalism institution, or setting it aside as a scholarship. But we decided that if we gained any benefit from it at all, it would color our future coverage of bitcoin," says Calore. "So we just destroyed the key, knowing full well that it could eventually be worth six or seven figures." McMillan then posted a story announcing the key had been ripped to pieces.

Throwing Away the Key

To deal in bitcoin, you need at least two different keys, one public and one private (newer security protocols allow you to add more private keys). Together, the combination of codes lets you trade Bitcoin without an intermediary like a bank. You can look up WIRED's public key to send us money, and then in theory, we could use our private key to access those funds—had we not destroyed it. It's extremely unlikely we could successfully guess the code: it's 64 digits long and no one remembers what it was.