Ben Bernanke

Among other objectives, liquidity guidelines must take into account the risks that inadequate liquidity planning by major financial firms pose for the broader financial system, and they must ensure that these firms do not become excessively reliant on liquidity support from the central bank.

Leverage is great when it works, and when it doesn't work, it creates a lot of issues. So I think if you limit the amount of leverage that people can borrow, or that banks can borrow, I think you'll find that you'll have a lot less issues going forward.