FabHK

That is a very naive take. First, the trust in crypto is extraordinarily expensive, as Budish's famous "The economic limits of Bitcoin" paper shows.

Second, the crypto bros running Bitcoin have reverted 20+ blocks on at least two occasions when it suited them to do so, and Ethereum has famously undone the DAO hack. Oh, and then of course you have all the bugs in smart contracts that can't be fixed. So the notion that "code is law" is laughable, and the notion that it's desirable is misguided, too.

Third, there's the oracle problem. Keeping track of bits in a ledger is a solved problem and has been a solved problem for a long time. The issue is correlating it with the real world. In your example, what if the student pays, then the teacher doesn't teach? How is the money flow reverted? If the student can just revert it, what happens if the student pays, the teacher teaches, and the student then reverts the payment? You need the legal system, and external adjudication, one way or the other.

Crypto adds nothing but idle speculation and the circumvention of (largely sensible) rules and regulations.

It was easier than that. There was a premium for Bitcoin in China and South Korea (the "kimchi premium") for quite some time due to capital controls. People in those countries would buy Bitcoin domestically (driving up the price there), send them to exchanges abroad, and sell them there, thus having taken their money out.

If you wanted to run the arbitrage, you'd buy Bitcoin cheap abroad, send them to China or Korea, sell them expensive, and now you're stuck with fiat in China or Korea which you can't take out, either. BitMEX founder Arthur Hayes was closing the loop in the early days by frequently crossing the border from China to Hong Kong with a backpack full of cash. SBF and Alameda claimed to have made their early money similarly by finding a way to close the loop on the kimchi premium.

Indeed. They have instead been solved by mobile-phone-based systems like Mpesa in Kenya and neighbouring countries.

Good. I also used to look at crypto with curiosity, but now think that

a) blockchain has no technological merit (given that permissioned systems already allowed for robust distributed consensus even in the presence of byzantine nodes back in the late 1990's).

b) the one innovation it brings (permissionlessness) is overwhelmingly negative (who really needs the "no gatekeeper" property?).

c) blockchain is good for nothing except crypto and crypto kittens (due to the oracle problem).

d) crypto is good for nothing except speculation and the circumvention of rules and regulations (which, like it or not, are mostly sensible).

Concretely for example on your point (it "let's some people keep their savings safe from dictatorial countries") - this would be trivial to offer for any bank using 1980's technology (offer an USD account just with username or password, no KYC), but it would also obviously be illegal and be shut down.

Making it harder to shut down - that's the one innovation crypto brings. But shutting it down is what we should be working towards.

The point of crypto is a) idle speculation and b) the circumvention of (mostly sensible) rules and regulations.

Estimates are that over the past few years, more than a third of the DPRK's foreign exchange income came from crypto. The legal exports were less than $0.5 bn, the rest is from more murky sources, including $1-2bn of crypto hacks in recent years.

1) The coins belonged to customers, but were in Binance wallets (thus under control of Binance) - that's how exchanges work. You send them your coins, then you can trade.

2) You can't freeze Bitcoin transactions (well, the crypto bros running it could if their majority wanted to, but they don't want to), but some of the stolen coins were stablecoins like USDT and USDC.

And fiat-backed stablecoins are ipso facto centralised (someone needs to 1) take receipt of fiat and issue coins against that, 2) custody that fiat and hold on to it reliably, and 3) return the fiat when given back the coins). You can then with the private key send the coins back to the issuer, but the issuer can refuse to give you the fiat.

However, many stable coin smart contracts are even more powerful: they give the issuer an authorized control account that can add a wallet address to a blacklist. The contract checks that list whenever someone tries to move the token; if the address is blocked, it rejects the transfer. Then the balance can’t be moved.

There’s a small difference: USDC blocks transfers both to and from a blacklisted address. USDT generally blocks the address from sending USDT, though it may still receive USDT. Tether’s contract also has a separate function that can destroy tokens held at a blacklisted address; that is distinct from simply freezing them. Note that when they destroy tokens, Tether keeps the cash - so it's a transfer from the criminals (or whoever held the tokens) to Tether. (Tether can then re-issue the coins and hand them back to law enforcement or the victim, but that's a separate step.)

It's well understood that crypto (scams, hacks) has contributed a third to half of the DPRK's foreign exchange income over the last few years.

Indeed.

However, it does not necessarily apply to algorithmic stable coins (Terra) or crypto-backed overcollateralised coins (DAI). That's why I said "fiat-backed".

Arguably any fiat-collateralised stablecoin is ipso facto centralised and trusted (someone needs to 1) issue the coins only against fiat collateral and then 2) hold onto that collateral reliably and 3) return it upon presentation of the coin), and at step 3 they can always say "no, we won't give it to you".

In other words, even for Apple, Harlow's razor applies...

Per family member, of course.