Observed arrival · 2026-11-03
お漏らし: Japan’s Public Data-Breach Register
A searchable register that sorts publicly announced information-leak incidents by the kind of data exposed and the number of people affected.
- For
- People comparing publicly disclosed data breaches in Japan
- Worth noticing
- My Number, bank-account, or card data triggers at least Level 3, even when the affected-person count is unknown.
Field notes
The homepage reports 326 cases and offers newest-first and institution-based browsing. Its four levels are determined mechanically from disclosed information types and affected-person counts: account, card, or My Number data sets a floor of Level 3, while Level 4 requires at least one million affected people. The site says cases without a stated count are judged by information type alone, and cases lacking enough detail for a type are marked unclassified; currently it reports zero unclassified cases.
Observed signals
Read the marks
Editorial observations of this landing page, not a rating.
One card from the complete issue