Unauthorized Access to Arcadia Alert System May Have Exposed Contact Data

Overview

• Arcadia, the operator of the SpeeCAN RAIDEN municipal alert platform, reported suspicious activity consistent with unauthorized access that it first detected on October 11 and disclosed to affected cities on October 13.
• Several local governments using the service have announced possible leaks of registered contact data, with Yokosuka reporting about 58,920 affected records, Nagasaki about 28,432, and Sasebo about 11,800.
• The exposed fields reported by municipalities include names, email addresses and phone numbers, and one city said roughly 2,200 municipal employee names and emails may be among the records at risk.
• Many municipalities have suspended automated mail distribution from the platform, shifted alerts to official websites, social accounts or public-address systems, and warned residents not to click links or open unexpected attachments.
• SpeeCAN RAIDEN is used by roughly 700 municipalities nationwide, so the vendor-led and independent investigations must still determine the full reach and whether the leaked data have been misused.