Mechanically speaking, a currency crash is a run on a country's hard currency reserves. Since the €-Mark is hard currency for €-zone members (thanks to the ECBuBa's idiocy), a systemic bank run would be a currency crisis in every way that matters.

May I point out that the run is already underway and has been for many months?

Back in May 2011:

German banks target worried Greeks in Germany

Greeks worried about a debt restructuring or a euro exit increasingly transfer their money to banks abroad, Bild-Zeitung reports. According to the mass circulation tabloid German banks such a savings bank in Munich have posted signs in their windows advertising in Greek and German that Greek costumers will be advised in Greek. According to the paper €30bn have already been transferred from Greece abroad since the crisis started.

Of course this puts a strain on the Greek banks which only increases their dependence on the ECB. For Greeks, another of the refuges, apart from Germany, was Cyprus which has always acted as an offshore banking center for Greece. Now Cyprus is in its own crisis.

But it's not just Greece and it's not just since last year. Remember these charts by Martin Wolf?

The top left chart indicates that the ECB has accumulated large claims on other central banks - this is the result of money flowing from the periphery to the core. Nothing surprising there, as the trade imbalances are structural and have persisted over the entire life of the Euro. However, the top-right chart indicates that the claims among central banks have developed only since the financial crisis started in 2007/8. So it's not  result of trade imbalances as one might have guessed, but of flight to safety.

And now, as we know, not even Euro assets in Germany are "safe" enough and people are piling on the Swiss Franc or (after the Swiss National Bank had enough of the Eurozone exporting deflation to it) to the Norwegian Krone.

So, yes, the run on the Eurozone banking system is well underway. It was bad enough in April already for

Bundesbank open to capital controls as a last line of defence

Bundesbank board member Andreas Dombret told Börsenzeitung that capital controls can be introduced by countries as "a last line of defence". "If they are used, it should be done temporarily and in a transparent and targeted manner", Dombret said. In combating high inflows of capital countries need to define a hierarchy of things to do. "If after that the inflows persists, capital controls can be considered", Dombret said. Capital controls were up until very recently a taboo and have only been proposed last week by the IMF in a position that was controversial among certain member states.

But he's talking about inflows of capital. Is he talking about Switzerland, rather than, say, Greece?

Economics is politics by other means