4. Nationwide Insurance, Allied Insurance Companies
An attack on a network used by both the Nationwide Insurance Company and the Allied Insurance Companies breached personal information of an estimated 1.1 million customers and applicants. The Oct. 3 attack netted a wealth of information, including names, Social Security numbers, driver's license numbers, date of birth and possibly marital status, gender, occupation and employment information. Medical information and credit card numbers were not believed to have been breached. Although the number of breaches is far less than a number of the exploits placed lower on our countdown, the value of the information stolen raises this case to a higher level.