One of the better summaries of the situation from Bill McBride of Calculated Risk:
δίλημμα: Dilemma. There is no good choice on Sunday.
Poor fiscal policies led to the need for a bailout. And the poorly designed bailout program has crushed the Greek economy. Now the creditors want more of the same, expecting a different result; so voting “Yes” seems like the definition of insanity. But a “No” vote will mean complete chaos.