27 Biggest Data Breaches Globally (+ Lessons) 2025 | Huntress

This report catalogs the largest global data breaches and leaks from the last ~20 years — including a June 2025 Chinese Surveillance Network leak of 4 billion records — outlining affected records, data types exposed, common causes (misconfiguration, scraping, unpatched services, human error), consequences (identity theft, financial and reputational harm), and recommended mitigations such as encryption, MFA, patching, and security awareness.