Top 10 Worst Data Breaches in History

The 2013 Yahoo data breach, which affected all 3 billion user accounts, is considered the largest data breach in history by number of accounts compromised.

Major data breaches often result from weak or stolen credentials, unpatched software vulnerabilities, insider threats, or sophisticated phishing and social engineering attacks.

Change your passwords immediately, enable two-factor authentication, monitor your financial accounts for suspicious activity, and consider freezing your credit to prevent identity theft.

Technology, healthcare, finance, and retail industries are most frequently targeted because they store vast amounts of sensitive personal and financial data.

Consequences can include regulatory fines, lawsuits, loss of customer trust, reputational damage, and significant costs for remediation and security upgrades.