It's a big number that only tells part of the story. The number of banks that have failed so far this year topped 100 on Friday – hitting 106 by the end of the day – the most in nearly two decades. But the trouble in the banking system from bad loans and the recession goes even deeper.

Dozens, perhaps hundreds, of other banks remain open even though they are as weak as many that have been shuttered. Regulators are seizing banks slowly and selectively – partly to avoid inciting panic and partly because buyers for bad banks are hard to find.