The Ponemon Institute report, 2006 Annual Study: Cost of a Data Breach
Understanding Financial Impact, Customer Turnover, and Preventative Solutions, is based on a review of 31 companies which lost personal information and were required by law to report it.

Together, these surveys demonstrate the extreme cost consequence ($182 per record and an average of $4.8 million per incident based on an average of 26,300 records lost) of companies breaching the confidential data and underlying trust of their customers. With the single largest cost being customer turnover, the cost to brand and corporate reputation can be the most long-lasting effect.