Interest to private information
Introduction
 The leak of private information in many companies increase the concern over management of private information.The services that neglect the private information will be shunned by the users.
When the law protecting personal information has been formulate, the company that neglect the private information is difficult to servive.The word "private information" we here in the news often indicates the information that can identify individual user.
Of course we have to think about the protection of private information, but we also have to think about the usage record of the service.
Usage Record and Private Information
 The reason why the service provider colect the usage record is that they could know the user's needs and provide the service that satisfy those needs.
Most of the services store the usage record with the private information per user.
 This is very convenient and leads to flexible service, but the risk to the leak of these information is very high.