That's exactly the point. If you define the universe to include only Bitcoin, then yes, transactions are final. But if you define the universe to include the real world, then the answer is no, not really -- governments will almost always find a way to reverse the transaction, whether it's seizing your private key, or holding you in contempt of court until you divulge it.

The transaction was final though, in the real world. The fact that the government can physically find your private key (or physically compel you to give it to them) and use it to make new transactions is irrelevant. All you're pointing out is that after you receive money in a transaction you can later participate in a different transaction using that same money.

To the entity holding the coins, whether it is a single Bitcoin transaction as per the protocol of Bitcoin, or multiple transactions, makes no difference... ultimately they will or wont be holding a certain number of Bitcoins. To then say, "well technically that was _two_ transactions" seems irrelevant, since to the entity (no longer) holding the coins, things have been effectively reversed. I think may just be highlighting a disconnect between the writer of the article using the term transaction as understood by a layperson, and people who want to use the term transaction as per specific meaning of a particular protocol.

> To the entity holding the coins, whether it is a single Bitcoin transaction as per the protocol of Bitcoin, or multiple transactions, makes no difference... ultimately they will or wont be holding a certain number of Bitcoins.

But to the entity who received the coins, it also doesn't matter where the coins went after someone took them by force. If you get paid for a day's work in cash and a robber steals it on your way home, you wouldn't say that your work payment transaction was reversed or that it hadn't been finalized up to the point of the robbery.

I think that example breaks down for the laymen understanding of a transaction, since the robber is a different party than who gave the coins in the first place.

What if an employer paid you in coins, so you take your coins and go home, then tomorrow your employer decides to take back the coins they gave you since they were not happy with your work (or they're just jerks)? I think that would fit the layman understanding of "this was undone!" (i.e. the transaction wasn't final). If in this case, the underlying financial engines used two, none, or one transaction (as specifically defined by that engine), probably wouldn't matter to the one who no longer has their coins.

> I think that example breaks down for the laymen understanding of a transaction, since the robber is a different party than who gave the coins in the first place.

The government is certainly a different party that wasn't involved in the original transaction, right?

> What if an employer paid you in coins, so you take your coins and go home, then tomorrow your employer decides to take back the coins they gave you since they were not happy with your work (or they're just jerks)?

This can definitely happen, at least with checking accounts. It has happened to me once because an employer accidentally double-paid everyone, and they were able to withdraw one of the payments from our accounts. I'm not sure exactly how that works. It could just be that your employer essentially has full access to your checking account since you gave them your account and routing number. Incidentally, I was always curious what would have happened if I had moved everything out of my checking account before they make the correction. But regardless of how it is actually implemented in the banking system, it's pretty clear if your employer erroneously removed funds from your bank account, or if you cashed out the accidental second payment then quit your job, it would again just come down to the legal system.

Your example with the employer is not possible with Bitcoin, unless for some crazy reason you share your private key with them.

It is not "reversing the transaction", it is just seizure. If you have spent the Bitcoin on a lamborghini, government will confiscate the lambo. Criminals however typically spend the stolen money on hookers and drugs. Seizure or confiscation has nothing to do with "reversing the transaction", calling it that is just stupid, mixing terms unnecessarily is just unnecessary and confusing here.

If you make a Bitcoin address, memorize the private key, and never write it down ever, then the only way for anyone to "reverse" transactions is to force you to physically say or write down the private key. This transaction finality seems to be orders of magnitude more final than a credit card transaction or a bank transaction.

So sure - it's technically reversible. But is this really a practical argument? It's like saying nobody is safe in public because you can be a victim of a terrorist attack any any moment. It's alarmist and practically wrong even if technically true.