[joosters]

> Nobody withdraws millions of dollars in physical currency

I'd suggest that the hackers who manage to alter their balance are exceedingly likely to be the kind of people to try and obtain a physical withdrawal of their wealth!

But even in electronic form, there is some settlement going on behind the scenes. Let's say I hack my bank and give myself $100 billion dollars, then try and transfer this to another bank in a country with a suitable lack of extradition treaties. No receiving bank is going to blindly accept a transfer in of $100 billion. Do you think they just take the other bank's word for it, that they are good for the money?