The Indian subsidiary of online deals giant Groupon has accidentally published email addresses and passwords of its 300,000-strong subscriber database, reports and the company said. Daniel Grzelak, founder of the Internet security website shouldichangemypassword.com, found the security breach of sosasta.com while running a Google search for publicly available databases. \"A few hours and tweaks later, this database came up,\" he told the Internet security site risky.biz. \"I started scrolling, and scrolling, and I couldn\'t get to the bottom of the file. Then I realised how big it actually was.\" Sosasta.com, an online discount portal acquired by Groupon in January 2011, alerted its subscribers Tuesday and posted a message on its Facebook page asking users to \"change your Sosasta password immediately\". \"Over this weekend, we have been alerted to a security issue potentially affecting subscribers of Sosasta. We wanted to let you know that the issue has been brought under control and your accounts are secure,\" the message said. Grzelak\'s website shouldichangemypassword.com holds a database of 1.3 million compromised email addresses, allowing users to check if their own email address is among those deemed unsafe. \"There are thousands of these databases indexed by Google,\" he told Risky.biz. \"This just happened to be by far the biggest I found.\" Groupon said it would review Sosasta\'s security procedures and put in place \"measures designed to prevent this kind of issue from recurring,\" risky.biz reported. \"Groupon takes security and privacy very seriously. Our users\' trust is of paramount importance to us and we deeply regret this incident,\" it quoted the firm as saying. \"This issue does not affect data from any other country or region.\" Groupon, based in Chicago, announced plans to go public earlier this month, after turning down a $6 billion takeover offer from Google last year. It currently has 83.1 million subscribers and operates in 43 countries. The company operates on the principle of collective buying, negotiating with businesses to offer discounted purchases which come into effect when a minimum number of subscribers agree to pay for the same deal.