It's not the banks, per se that they are afraid of. It is the panic than can ensue when there is a lose of confidence by investors. We have seen that happen many times under various scenarios in many countries.
Maybe the answer is to not let banks/ brokerages got too big. I just finished reading
Too Big To Fail by Alex Sorkin and have gotten a few more books about the crisis of 2008 because I want to have a better understanding of what happened, why it happened and if anything has been done to change the way things are done and to provide much stronger protections.
The books include:
The Monster - How a gang of predatory lenders and wall street bankers fleeced America - and spawned a global crisis. It's by Michael W. Hudson. Another book is
House of Cards by William D. Cohan. A tale of hubris and wretched excess on Wall Street. Finally
In Fed We Trust - Ben Bernanke's war on the great panic by David Wessel.
If I come up with any brilliant ideas I'll come back and post them. I'll pass them along to the powers that be too.