This is called a deposit run - and in the days of the internet you do not really need to put your bobble hat on and leg it: you can do it from a seat in Starbucks.

BBC: Tick, tock: The risks of depositor flight in Greece

Russian banks tend to be small, badly run, and do little deposit-taking and lending.

ECONOMIST: Russia's central bank

That could trigger a bank run, particularly when the remaining deposit controls are lifted.

ECONOMIST: Argentina's economy

Another possible response to a bank run would be the introduction of euro-wide deposit insurance.

FORBES: Would A Greek Exit Really Be Manageable?

Kroll's software had to synch not only with banks' mainframes but also with programs run by intermediaries--such as Harland Financial Services and FIS--that track deposit and loan data and integrate them with banks' general ledgers.

FORBES: Entrepreneurs