I knew someone would get around to saying this...

... I just didn't expect it to be Tim Geithner.  To quote:

To sum it up, Geithner confessed that worldwide monetary policy was too loose too long creating a huge bubble in asset prices. Basically, there was too much money chasing investments. Like flood waters, money seeks ever higher returns, pushing prices of real estate and commodities at rates exceeding 15% annually in 2004 and 2005.

But, I thought it was greedy bankers and lack of regulation that caused this (just kidding, I didn't really think that).