<p><advertisement></advertisement>The state's largest health insurance company has warned 70,000 Georgians that their personal medical information, Social Security numbers and credit card data may have been wrongly accessed because of a Web site security breach. The security problem at Blue Cross and Blue Shield of Georgia is part of an even larger Web site breach of its parent company, WellPoint, which this month sent warning letters to 470,000 people across the country. Information was exposed for five months, said company spokeswoman Cindy Sanders. It affected applicants under the age of 65 who were applying for individual policies. She said the problem occurred following a faulty Web site upgrade in October.</p>