sachs, charged with civil fraud in connection with its subprime mortgages. the securities exchange commission alleges the investment firm defrauded investors by selling securities to one group while letting another bet against them. the firm calls the charges, quote, completely unfounded. tax payers already cover their room and board, turns out the irs has been paying prisoners too. cnn's john zarrella looks at a tax scheme that has raked in millions. >> reporter: just a routine search of a jail cell. officer mark lindhback didn't expect to find much. >> after the inmates exited the cell, went over, basic, pulled up the mattress, had some items on his mattress, additional items underneath the bunk. >> reporter: the items, tax form and address book with social security numbers, birth dates and cheat sheets for filling out returns. that was december of 2006. what lindhback had stumbled upon was a lucrative income tax fraud