Good luck renewing your passport in a case like that. Extradition is unlikely, but getting back into the US could be sticky to say the least.
An understatement, to say the least.
> but getting back into the US could be sticky to say the least
Really? They're not going to allow you back into the USA, or arrest you at the border for defaulting on a loan? That doesn't sound very credible at all. Any evidence to back that up?
Defaulting on student loans is a civil debt. Filing fraudulent tax returns is a crime. I have never heard of someone being extradited or having their passport cancelled for defaulting on a civil debt (probably because governments have no direct interest in civil debts per se)
http://www2.ed.gov/offices/OSFAP/DCS/treasury.offset.payment...