I'm not sure it's the fault of bankster crooks this time. If I had to point any fingers, it would be mostly on the political power games that are being played, with every power-hungry radical trying to save face by draging things to the last possible second.
The banks of Greece are on a limited supply of money, people began a sort-of bank run (ATM run more like it), so until the referedum they're trying to keep capital flight under control.... more or less