Japan Police Investigate Exposure of Employee Data in App Breach

A cyberattack targeting services operated by disaster preparedness app provider Arcadia Inc. may have exposed personnel information belonging to tens of thousands of police officers and civilian employees across Japan, according to reports from multiple prefectural police departments published by Asahi Shimbun on October 21, 2026. Authorities are investigating the potential exposure and whether the affected information has been misused.

Kanagawa prefectural police reported that names and email addresses belonging to approximately 16,000 employees may have been compromised. The department said nearly 17,000 officers and civilian employees were registered in Arcadia's emergency response system, which monitors staff safety and work availability during disasters.

Other departments also reported potential exposure involving thousands of personnel. According to Asahi Shimbun, Saitama prefectural police identified approximately 13,000 potentially affected employees, Fukuoka reported about 11,000, Aichi reported 15,000, and Kagoshima reported 2,200.

The information potentially exposed varies by department. Tochigi prefectural police reported that data belonging to approximately 3,900 officers and civilian employees, effectively its entire workforce, may have been compromised.

According to Tochigi prefectural police, the potentially exposed information includes names, departmental affiliations, job titles, mobile phone numbers, and email addresses. The department's report indicates that the incident may involve more extensive personnel information than the names and email addresses identified by Kanagawa prefectural police.

Gunma prefectural police are also investigating a possible data leak, according to Asahi Shimbun. The report did not specify how many employees may have been affected in Gunma or identify the categories of information potentially exposed there.

Arcadia Inc. operates the emergency response services used to monitor personnel safety and availability during disasters. The reported incident has prompted multiple police departments to examine whether employee information registered in those services was exposed through the cyberattack.

Authorities are investigating whether any of the potentially leaked information has been misused. The available reports do not establish whether the exposed records have been used for unauthorized purposes.