"For Americans struggling in this economy, an advance on a paycheck can be a lifeline. These advances - also known as payday loans - have become a fast-growing business online, with nearly $11 billion lent out last year.

The money often comes with crippling interest rates, as CBS News chief investigative correspondent Armen Keteyian found for this report in partnership with the Center for Public Integrity.

Ramon Zayas was suffering from prostate cancer and facing mounting bills.

So he and his wife got a $250 payday loan from an online lender 500 FASTCASH. It charged an annual interest rate of 476 percent. Zayas thought he was paying off the loan, but confusing fees, and the high interest eventually pushed the cost to $125 a month - on a $250 loan. Like a lot of people, he couldn't keep up with the soaring costs.

Because of cases like this, 17 states have effectively banned payday lending. But Ramon Zayas' lender is shielded from state laws because 500 FastCash is owned by an Indian tribe. Today, an estimated 30 online payday lenders partner with American Indian tribes.

"If you can become affiliated with a tribe, and be able to avert local and state laws, in my opinion, apparently loan sharking is legal in this country," said Rick Brinkley."

Get the Story:
How "payday" lenders pull off crippling rates (CBS News 9/26)

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