Most of that debt is owned by Americans, who incidentally also own 393.3 million firearms - twice as much as every police force and military in the world combined[0]. I shudder to imagine what 100 million pissed off gun owners would do when they find out that there's going to be a 50% haircut to their life savings.
[0] http://www.smallarmssurvey.org/fileadmin/docs/T-Briefing-Pap...