Yes, a good example of prison currency. Another form of currency (in prison but also outside) is sex. And it perfectly fits GP’s “argument” that “some people like it, some people pay with it, some people want more” and all that.
We can either take the “everything is a currency” route but that gets us nowhere, or accept the official, legal, and recognized definition. The “ill conceived” argument based “only” on facts so to speak.
What's your source for an "official, legal, and recognized definition"?
The definition used by economists includes much more than just fiat money. The definition in most dictionaries includes anything used a medium of exchange. Paper money isn't even the most common form of currency these days (beaten by credit cards, checks, and electronic funds transfer).
As an example the ECB (European Central Bank, central bank for the Eurozone) declared exactly that [0], as I said in my original comment. The ECB, the Fed, the SEC (as you can read from the current HN article) all see crypto as securities and way too volatile at this time (something you don't want in a currency). This may change in the future but it doesn't change the current state of fact. Another important aspect is that accepting it as an official currency means it will have to be regulated like a currency, rather than a security or (mostly) unregulated like today.
The only major central bank that is truly dabbling in crypto is the PBC (that's People's Bank of China) and I think the consensus among people in the sector is that it's really a speculative move, just like most ICOs.
Edited for courtesy. It initially felt like one of the classic methods of arguing a fact on HN: request citations worthy of a PhD thesis for every single word. It's unfortunately all too common here to deter anyone from contradicting.
Sorry, pressed for time. But I don't think missing an unsourced comment from earlier in the thread and asking a question about it deserves that kind of response.
I asked the question hoping to learn something, and I did. So thanks for that, if not for the attitude.
Also because I noticed only now, whether currency is paper, electronic, or any other material is not actually what tells currencies apart. But while classic legal tender is backed by the goods and services of the country that uses it (I know this part is a bit arguable but let's go with it), crypto is more or less backed by nothing but the trust that the blockchain can't be hacked. One bad hack and the value of BTC becomes 0, something very hard to do with a classic currency but catastrophic if it happens. It's also very susceptible to volatile bouts, as seen before. BTC could be a "real" currency but it would be an overall bad one that could not replace the classic currencies in it's current form. It doesn't mean it can't become one but it would have to change in ways that would take it away from the current BTC.
Take a hypothetical CMU (Close04 Monetary Unit) backed by the value of my belongings. That's a token that goes up and down in value as I buy more stuff or my house gets more expensive, or as I issue more tokens (inflation). But it's only as valuable as the trust you have in me and the laws that prop up that trust. If I sell all my stuff and disappear your token is worth nothing and there's very little you can do. There are no protections, there's no legal mechanism that prevents me from selling my stuff. For a coin to become a proper currency it needs some of those props. Unfortunately most people are internet educated in these aspects so they only understand once they get swindled. Every time a cryptocoin is abused, an exchange goes bust, you see a lot of converts and crypto regulation starts to sound better.
They don't, you can use any medium for exchange. They have monopoly in deciding what is and what isn't an official currency.
As for the rest of your question, the people give them the power as part of the democratic process. Many people realized that whether they like it or not the little protection they get from a government is better than nothing. And it's enough to look at people's reaction when they get swindled out of their completely unregulated coin: ask the government to fix it and punish the swindlers.
We can either take the “everything is a currency” route but that gets us nowhere, or accept the official, legal, and recognized definition. The “ill conceived” argument based “only” on facts so to speak.