The government today said, the debit card customers need not worry in view of data theft. Talking to media in New Delhi, Secretary in the Department of Economic Affairs Shaktikanta Das said, the probe is underway and every necessary action will be taken to address the possible threat. <br/><br/>On a query, Mr Das said, cyber security is an important matter and detailed reports have been sought from the banks over security breach. Meanwhile, Talking to AIR, Deputy Managing Director of SBI Manju Agarwal said, the bank asked the customers to change the pin number soon after it came to know about the data breach of debit cards. <br/><br/>She said, the cards of those who did not respond to the bank's SMS were blocked. She said, new cards will be issued within three to four days. <br/>However, cyber expert Pawan Duggal told AIR that this was the biggest reported breach of data security. Mr Duggal said it is a wakeup call for the country to strengthen its cyber security system. <br/><br/>Earlier, State Bank of India in a statement claimed that its systems are absolutely secure and customers can continue to use their Debit cards securely. However, they should use fraud prevention facilities provided by the bank.