[audleman]

But the transactions were final, just as it would be if your employee stole the day's cash and escaped somewhere you couldn't find them. Reversible would mean you could press a few buttons on the cash register and poof, the money's back in it and not the pocket of the thief.

Tracking down said thief and taking the bag of money back in this metaphor constitutes a new transaction. As is subpoenaing Dropbox and gaining access to the poorly encrypted list of private keys from these Bitfinex rapper/hackers.

[wpietri]

I don't think that's true from the perspective of the employer with the stolen money. The employee took the cash. The employer just wants to hit undo on that. They don't see it as a new transaction, but the reversal of the old one.

Of course, this is all a bit arbitrary. So I don't think we'd have much to disagree if cryptocurrency proponents were open about that. But what we get is a lot of them talking about 100% irreversible transactions. That may be true in the technical jargon of a particular system, but is definitely not always true in the broader social context or in casual uses of the term.