SHINDO4

Shizuoka City

Pupils~9,200people

LEAK CONFIRMEDPostal address / Full nameInsider misuse · Closed (final report)

Open in the live monitor ▶
Disclosed
May 1, 2026
Detected
Apr 1, 2026
Detection to disclosure
30 days
Leak
Leak confirmed
Type
Insider misuse
Status
Closed (final report)
Security spend
Not checked yet
Compensation
Not announced

What leaked

IdentityName
ContactAddress

How many

  • Pupils ~9,200 people

Who is affected

  • Pupils at 15 elementary and 5 junior high schools

Cause

The city board's PTA guidelines banned sharing without consent, but the schools did not follow them

Timeline

  1. Fiscal 2024 to 2026
  2. Found through a parent's inquiry
  3. First disclosure

Response

  • Governance / committee
  • Data deleted
  • Notified individuals

Re-sent the rules to all schools and instructed principals; explained and apologized to parents; PTAs to return and destroy the data

What you should do

  1. Watch for unexpected mail or invoices; your address is hard to change
  2. Check the company's notice to see if you're affected

Lessons for companies

  1. Report to the PPC: preliminary in 3–5 days, final in 30 (60 if malicious)
  2. Run red teaming and AI-assisted hardening, and publish how much you invest

Sources