http://www.alternet.org/how-american-corporations-and-super-rich-steal-rest-us
"Exxon has almost 80% of its productive oil and gas wells in the U.S. but declared only 17% of its income here. The company used a theoretical tax to account for 83% of last year's income tax bill, and paid less than 2% of its total income in current U.S. taxes."
