Central banks cannot prevent unraveling of global economy?

Satyajit Das opines that the tools available to central banks are inadequate to address the scope of the global economic problems we face.  The black box or shadow economy may involve the unwinding of “innovative” financial products/derivatives such that monetary and fiscal policy simply will not work this time. 

http://www.boston.com/bostonglobe/ideas/articles/2008/01/27/the_black_box_economy/