With the credit market in cardiac arrest this is interesting. The Fed has just declared a monopoly on shorting the market.
Let me walk you through the process:
1) A bank gets in a cash pinch
2) With no where to turn, the bank has to ask the Fed for money
3) We all saw, FNM, FMC, LEH and AIG. We know how this plays out - we sell.
4) Stock slip tightens cash crunch
5) Bank get's loan if and only if the Treasury gets controlling interest in warrants
6) Government owns former bank's assets
7) Government gets to fire-sale bank assets to buddies

You get to pay the difference in tax