Who Owns the World’s Sovereign Debt?

This monster graphic comes  from the IMF.

It's loaded with interesting factoids about who owns how much of each country's debt. Global Macro Monitor points out 
the fact that "47% of the US$14.7 trillion U.S. federal government debt is held by the Federal Reserve and the government itself, such as the Social Security trust fund." (not China)

Those graphs with the biggest red color portion are in trouble:-