A growing number of customers affected by a string of recent personal data breaches at major commercial banks and other financial firms appear to be turning to class action lawsuits in pursuit of compensation, according to industry officials, Wednesday. The banks have pledged to fully compensate customers whose losses, including those from voice phishing scams, are found to have directly resulted from the leaks. But proving that a loss was caused by a specific data breach can be difficult in practice, and the banks have yet to set out clear standards for determining which claims would qualify, prompting some victims to resort to legal action. Seven financial firms have reported information leaks so far, including three of the country’s largest commercial lenders — Shinhan Bank, KB Kookmin Bank and Hana Bank. Shinhan reported the largest breach, affecting around 25,000 people, followed by 119 at KB Kookmin and 89 at Hana Bank. The exposed data includes customers’ names, contact details, resident registration numbers, annual income and loan limits. The combination of personal and fin