To bankrupt America, all you have to do is convince everyone to withdraw all their money from the banks at the same time.
Ie. what people just did with the proof of keys event, if people did that to banks... Boom!, the ponzi known as fractional reserve banking would collapse.

Of course that's not going to make your personal situation any better, in fact you would be much worse... And i can imagine the effect on the world economy considering that too many countries follow the mistaken Chicago school of economy (fast growth by debt) and its endless bubble/crash cycles.