Nobody is saying that traditional financial institutions are perfect, but at least they are regulated and at least there are checks and balances in place. By and large the examples people roll out of these institutions behaving badly are examples of the regulators and legal frameworks working the way they are supposed to.

Knight capital were in a risky business and they blew it. It happens. But they're the exception, not the rule. In the wonderful world of Bitcoin, the goings on at MtGox looks like the rule, not the exception.

Excuse me, you must have forgotten about a certain global financial meltdown in 2008?

Knight capital was a cock up in a high risk trading env. They paid for that.

HSBC was money laundering which is basically the entire purpose of a bank.

NatWest was a process cock up.

However no money went "oops we lost it" and was never seen again. At most, even with HSBC consumer withdrawal limits it's a minor inconvenience for a couple of days.

Much like mobile phone networks, people expect 100% uptime but that's unrealistic in practice. Always keep £200 rolled up in your mattress.

This is a very strong statement.

Do you mind backing it up, or is this just meant as a glib throwaway quip?

One of the functions of banks is indeed to hide the source and destination of your money. My grocer doesn't get to know who employs me; my employer doesn't see where I spend my money.

Yes, you can achieve that with cash, without directly involving a bank. But the money is still issued by a bank.

I'm not saying that it's impossible to achieve this level of information hiding without banks, but I can see where the GP is coming from in his argument.