Korea’s famous portal website Cyworld and Nate of SK Communications has been hacked on July 26th. About 35 million users’ private information including name, social insurance number, ID, password, email address, was stolen to a hacker suspected from China. SK Communications puts up a publication of apologies to this event on the homepage. They also inform users to change their IDs and passwords used in other websites to prevent potential victimization. The ‘victims’, users whose personal information was stolen, have created a Naver internet café to discuss about this situation. They have also showed a consideration of suing SK Communications. This was very unfortunate event for SK Communications because they have been prepared to expand their business abroad targeting to global users. It’s important to expand the size of the business, but users’ security on personal information has to come first.