It's amazing that two years after we found you can buy a credit default swap on almost any instrument, then torch that instrument and get paid off, that these banks didn't have the collateral to be able to write these contracts, Cramer added. To him, it's like AIG all over again and that, he noted, was a huge bailout.
RELATED: SCENES FROM THE GREEK PROTESTS
So what does this mean for U.S. banks?
Cramer thinks most every bank stock is a 'sell.' Some banks reportedly have more exposure to Greece than others, but Cramer isn't sure the reports are right. So he would stay away from all bank stocks right now.
While regional banks are immune to the Greece debt crisis, Cramer said the banking sector trades in unison. So he would stay away from these stocks until the smoke clears.
(Read More:5 Things Investors Need to Know On Latest Greece Crisis)
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