Double Taxation
I'm working on our taxes this weekend. It annoys me that we have to file U.S. taxes despite having earned no U.S. income. It's actually relatively painless, except for the calculation of our income which has to be done on a daily exchange rate basis. 
Thankfully we each earned well under the $82,400 federal cap (and the $80,000 Wisconsin cap...yes we even have file state taxes!), so we will not have any U.S. tax liability, it's merely the formality of filing the paperwork. We would only have to pay U.S. taxes if either of us earned the equivalent of $82,400 a year. The U.S. is one of the very few countries that double taxes its citizens. Most countries have agreements preventing double taxation.
Thankfully we each earned well under the $82,400 federal cap (and the $80,000 Wisconsin cap...yes we even have file state taxes!), so we will not have any U.S. tax liability, it's merely the formality of filing the paperwork. We would only have to pay U.S. taxes if either of us earned the equivalent of $82,400 a year. The U.S. is one of the very few countries that double taxes its citizens. Most countries have agreements preventing double taxation.