The document provides an overview of data breaches based on an analysis of publicly disclosed breach incidents from 2005 to 2015. It finds that while large, "sensational" breaches receive headlines, the majority of breaches are smaller in size. The most common methods of breaches are hacking and theft, while the most compromised records are personal identifying information. Healthcare, government, retail, and financial organizations are most commonly affected. Defenses against breaches are an ongoing challenge as attacks increase in sophistication over time.