By withdrawing all money from Greek bank accounts the Country is forced closer to bankruptcy - so the rhetoric in the media has a causal effect on Bank share prices and others in Greece.
In one weeks time is the meeting of the Trioka in Greece. After a summer lull, all the talk of eurozone collapse will return to provide and indian summer of hot air for the autumn.
What if anything can stop this cycle? I doubt myself it is possible, but when politicians are involved it maybe there is a massive printing of money or some other kind of mega-collapse that will allow Greece to continue in the Eurozone. the price for exit is a disaster of 2008 proportions, only this time piling into a much weaker Eurozone economy.