Variable annuities guaranteeing a minimum of 6% per year.?

I hav heard of and read of Insurance companies issuing variable annuities that will guarantee a minimum of 6% return on your investment even if the markets take a nose dive as they did recently.
The two insurance companies and their plans are: ING Life Pay Plus
and JACKSON Freedom 6. Are these plans legitimate and, if so, how can they guarantee the minimum 6% in a declining market?

They can afford to pay 6% on the savings part of your policy because they make a lot of money on the insurance (cost!) part of it. No bank gives money away, ever.