The Asahi Shimbun has won Japan’s equivalent to the Pulitzer Prize for its reporting into the sloppy handling of personal user information by the company that operates the popular social messaging app Line.

The Japan Newspaper Publishers and Editors Association announced the 2021 winners on Oct. 6.

In explaining its decision, the association described the investigative journalism as “the result of utilizing a reporting network that extended from Japan to abroad and was a warning to a society where platform operators have huge influence.” 

The first report, which appeared online and in this year’s March 17 morning edition, explained how the employees of a Chinese company contracted by Line Corp. were able to access the personal information of many Line users without an adequate explanation about how their data would be used.

The revelatory report was followed by another the following day that explained how video and other Line user data was being stored in computers in South Korea.

In the wake of these articles, Line said it had revoked the Chinese firm’s access and would move the data from the South Korean computers to ones in Japan.

Following that, the Ministry of Internal Affairs and Communications ordered Line to improve its operations in line with the Telecommunications Business Law.

According to a June announcement, Line had about 88 million users a month in Japan and about 187 million worldwide.

After the reports were published, several local governments suspended their use of Line in providing various services to residents, given the uncertainty over how the data might be used.

The last time The Asahi Shimbun won this award was 2018, when it ran a series of articles about falsified public documents by Finance Ministry officials.