August 30, 2023 Administrative guidance to Yahoo Japan Corporation

The Ministry of Internal Affairs and Communications (MIC) today issued written administrative guidance to Yahoo Japan Corporation (headed by Takao Ozawa, President and Representative Director, CEO) regarding the implementation of user notification and security control measures for the provision of search-related data.

1. Background, etc.

Yahoo Japan Corporation (hereafter referred to as “Yahoo! Japan”) provided search-related data to NAVER Corporation (hereafter referred to as “NAVER”) on a trial basis from Thursday, May 18 through Wednesday, July 26, 2023, from the perspective of development and validation of Yahoo Japan’s search engine technology. During this period, Yahoo Japan provided and allowed NAVER to use sensitive data such as location information from search queries of approximately 7.56 million unique browsers. Among these, location data specifically applied to around 4.10 million unique browsers. This was done without giving sufficient prior notice to the users. In addition, it was also found that sufficient security control measures had not been taken for the said location information, etc.

2. Details of measures, etc.

Today, MIC issued written administrative guidance to Yahoo Japan (see attached PDF), directing the company to implement the following measures and to report on their status.

(1) Sufficient advance notice to users
(2) Implementation of matters related to safety control measures