If bitcoin is controlled by no one, how can it be stolen?
I heard there was big news about two or three weeks ago where a couple supposedly had approximately four-and-a-half billion dollars worth of bitcoin stolen by the U.S. government. So, how did that happen?
Well, when the government seizes bitcoin, what they do is they get a hold of your private key.
Explained in simple terms, the way it works is you could have a bitcoin wallet…you could go to the app store and download a wallet right now, and in effect, it would be no different than Venmo. If you had a Venmo wallet, and you wished to send someone money, you could simply ask them to give you their address, you would plug it in, and you could send them the money.
But, the difference is that with Venmo, it would go through all the different stages, whereas with bitcoin, it would be peer-to-peer. Of course, you don't actually downloaded the bitcoin into your phone, just as Venmo doesn't actually download coins into your phone either.
What happens is you have a public address and a private key. So, the public address is like your bank account. So like right now, you could say, "Hey OANDA, I have a bank account at Bank of America. Here is my account number. Go ahead and transfer some money into my account using my account number."
And so bitcoin has a public address, and then there is a private key. Think of it like a locker system at a train station. Your locker number might be B-17. You could ask someone to go put an envelope in your locker by asking them to put it in Locker B-17. And anybody could know your locker number, but only you would have the private key, and that private key allows you (or anyone you give it to) to open the locker and put stuff in it (or take stuff out of it).
Now, when you have a hardware wallet, if you custody that yourself, it means you have control of your private key. In effect, only you can then open that locker. On the other hand, if you keep your bitcoin on an exchange such as Coinbase, for example, then Coinbase has your private key.
Now, I understand that in the world of bitcoin, they have a saying: "Not your keys, not your coins." So, whoever has the key, has control of the coin. This of course means that if you leave it on a central exchange, such as Coinbase, Kraken or Gemini, and they get leaned on or squeezed by a government, they might be forced to give up your key.
Think about it like in the old days, you might have some gold that you buried in the ground, and you would subsequently draw a treasure map. If somebody got a hold of that treasure map (your private key) they could get a hold of your gold. If you lost your treasure map (your key) you would also lose your gold (your bitcoin). One could think of it that way.
So, in that specific hack where the couple got all their bitcoin seized, what supposedly happened was the government raided their home, and the couple had put their private key into Google Drive. So all the government had to do was get in their computer, find their private key (their treasure map) and get access to the four-and-a-half billion.
So, you really have to protect your private key. That's the main thing.