SHINDO2

Suginami City

Personal data121people

EXPOSEDPostal address / NationalityMisdelivery · Closed (final report)

Open in the live monitor ▶
Disclosed
Jul 29, 2026
Detected
Jul 25, 2026
Detection to disclosure
4 days
Leak
Exposed, access unknown
Type
Misdelivery
Status
Closed (final report)
Security spend
Measures, no amount
Compensation
Not announced

What leaked

IdentityNationality, Full name
ContactPostal code, Address

How many

  • Foreign-national residents whose nationality was printed 121 people
  • Survey recipients 3,000 people

Who is affected

  • Residents randomly selected for the ward's lifestyle survey

Cause

Staff left the nationality field selected when exporting data for address labels and did not notice it when checking the printed labels

Timeline

  1. Survey forms mailed
  2. Anonymous inquiry that nationality appeared on the address label
  3. Error confirmed
  4. First disclosure

Response

  • Config review
  • Change process

System settings changed; a second staff member now checks output before and after printing

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. Use DLP: recipient checks, send delay, automatic attachment protection
  2. Report to the PPC: preliminary in 3–5 days, final in 30 (60 if malicious)
  3. Run red teaming and AI-assisted hardening, and publish how much you invest

Sources