Are Banks Tightening Credit to Force Congress' Hand?

An interesting theory I heard today: Banks and Wall Street may not be motivated right now to keep the credit markets working well. After all, if you're a firm holding millions in questionable assets that you might be able to sell for 20 cents on the dollar, maybe it would be a good idea to give Congress a little help in prompting the bailout so you can sell those same assets to the government for 50 cents on the dollar...or more.

I'm not much for conspiracy theories, but I could see how that might happen.