A lot of people don't realize that our entire financial system is eventually consistent. They think that when they go to an ATM and withdraw money, it's instantly gone from their account.

The reality is that in most cases the convergence is so quick it looks like it's instantly gone, but it's not. For example, if the ATM is unable to get your current balance, it will still complete the transaction.

That's why your card has a daily limit -- that's basically the risk tolerance of the bank on how much they are willing to lose if the transactions don't get converge quickly enough.