Canadians working in the U.S. have had fun with IRS because a type of Canadian registered (tax-advantaged) savings account is not recognized by the IRS as a registered savings account but rather a "passive foreign investment company" and IRS loves to make people fill out lots of paperwork. This is apparently because IRS rules haven't been updated in the 10 years since the account type has been created.
It's such a bureaucratic clusterfuck for a small business or consultant.
Unfortunately, there's little chance of normalizing the laws with international custom, since I can already see the attack ads about tax breaks for the wealthy.
A lot of countries tax foreign-earned income, but still US is a outlier along with Eritrea, with taxing foreign income of nonresident citizens.
Ahh, and I forgot to specify "non-resident". Sort by "taxes foreign income of non-resident citizens": http://i.imgur.com/hSsVmwd.png
Sorry.