America's biggest companies are playing by their own set of rules. According to a recent report from two major watchdog organizations, our nation's Fortune 500 companies have $2.1 trillion dollars stashed in overseas tax havens.

To put that number in perspective, it's worth noting that the entire federal budget for 2015 was only about $3.8 trillion.

This stunning report, called “Offshore Shell Games 2015,” was the result of a study conducted by Citizens for Tax Justice and the U.S. Public Interest Research Groups. They found that about 70 percent of these massive companies have subsidiaries in low-tax nations like Bermuda, Luxembourg, Ireland, and the Netherlands.

In many cases, those subsidiaries are really just PO boxes used to pretend like they do business in those nations.

By stashing money away overseas, those corporations have left taxpayers footing the bill for as much as $620 billion dollars of unpaid taxes. And, that means they're getting to benefit from our nation without contributing their share of the costs.

Michelle Surka of US PIRG said, “The American multinationals that take advantage of tax havens use our roads, benefit from our education system and large consumer market, and enjoy the security we have here, but are ultimately taking a free ride at the expense of other taxpayers.”

We give these corporations the privilege of doing business in our great nation, and they make a boatload of profits at our expense. The corporate powers have taken our pensions, reduced our wages, and destroyed our environment.

The least they could do is contribute their fair share of taxes, instead of skirting the system to make a few extra bucks for shareholders.

If corporations want to do business in the United States, it's about time they start pulling their weight.