US Downgrade: Somebody Knew, Huh?

When the market plunges and then is follows withing a day or so of big news like a credit downgrade, I always wonder if somebody knew. What about you?

But now I'm wondering if the market move is because of economic worries or because of a headline news event? Maybe if it's the latter then this selling is short-lived. Granted, the US does have a debt problem.

Just thinking out loud.