Is this stealing by whatever definition police/the courts currently use? Isn't it an intentional part of the design of a cryptocurrency that decisions are made by a consensus based on hashing power?
If you have 51% of the hashing power, you have control over that cryptocurrency; that's by design. Can you really steal at that point?
edit: to those replying, I'm not saying this double spend is ethically fine, or not theft in the common parlance. I'm saying it's not entirely clear to me a court would find this to be theft. Think about the Ethereum hard fork to undo the DAO hack; there, a majority of the hashing power undid a bunch of transactions. I wouldn't call that theft (because it was undoing a hack?) but it doesn't seem that different to this situation.
Uh, yes, you can steal. Just because the vault is open at a bank doesn't mean that you can walk in, take the money and leave, and then claim that it's yours because they didn't lock the door.
When you send money to an exchange, there's an understanding that the money now belongs to the exchange. The exchange waits 6 confirmations to ensure that the money is not easily stolen, but the money legally belongs to the exchange as soon as the transaction is sent.
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Also, a 51% attack doesn't give you control over the cryptocurrency. You still have to follow the rules of the system, you can't print extra money from thin air, you can't spend money you don't control, the most you can do is change the ordering of the transactions that have happened on the system. And a lot of times, those transactions have block height or block id dependencies, which means you are even limited in your power to do that.
A 51% attacker is not God. They have a limited set of actions they can take, and while certain forms of stealing are included in that set of actions, it's overall a pretty limited set of things that you can do.
It is not by design, it is a known weakness. The intent behind the actions also matters and it would be known to the malicious miner that to take these coins from exchanges would result in a loss to the exchange. So it would be illegal.
If however the miner maintained 51% + network share and then wrote some code to create new coins and adopted that code and mined blocks awarding himself 1000 coins for each block, he could legitimately do that and then sell those coins. Of course this could lead to the price dropping as soon as people realised what was happening and likely to happen before the attacker could send enough coins to an exchange to make the same sort of profit as in the situation in the article.
Code is law, bro. These fine chaps simply gathered enough resources to execute a slightly different code-path than before.
The folks whose value was stored in Bitcoin Gold should have read the source code before committing any funds to the blockchain. Had they done so, it would have been very clear that this feature was baked right into the source code.
And yes, this is sarcasm.... but only kinda sorta--bitcoiners wanna live in a Truly Free Unregulated Market, free from statist jack booted thugs stealing their wealth at gunpoint... guess what, double spend attacks where everybody loses is the end result. Sorry for their loss....
What exactly was stolen here? This isn't legally recognized money. And the spend was of the attacker's own coins. The exchange into another cryptocurrency or fiat currency is fraudulent I suppose, but isn't that on the transacting exchange?
They pretended to transfer to the exchange an item of value, and agreed to swap that item for a different item of value. They've defrauded the exchange / obtained a benefit by deception, like writing a dud cheque or something.
Fraud doesn't require "legally recognized money" to be involved. If you had some scam where you knowingly traded counterfeit collectable cards for real ones you'd be in trouble too.
Both the location of the victim and of the attacker could prosecute; the location of the victim is more likely to start the process since they'll receive the complaint.
Why would the legal tender issue change anything whatsoever?
Fraud and theft statutes in general don't have any specific limitations to what the stolen assets must be, it's sufficient if they have some nontrivial value. No matter if Bitcoin Gold is treated like a currency, a security, or other asset, the treatment of it regarding fraud or theft would be the same.
In general, this seems like a clear-cut case of fraud - there's a victim (the exchange) that suffered a loss (by allowing to withdraw the coins) by deception (the attacker "demonstrated" that they deposited the coins, but reversed it), and there's clear premeditated intent to arrange the scheme for the attacker's financial benefit.
The technical details of how the victim was convinced to accept the deal and how the funds were extracted, and what's the nature of the currency are not particularly relevant to whether it's fraud, they'd be used only as evidence to show what happened and to evaluate the amount of loss.
