Each state has different laws about how people need to be notified about data breaches. U.S. mail is generally the lowest common denominator across states. See

Each state has different laws about how people need to be notified about data breaches. U.S. mail is generally the lowest common denominator across states. See https://info.digitalguardian.com/rs/768-OQW-145/images/the-definitive-guide-to-us-state-data-breach-laws.pdf https://info.digitalguardian.com/rs/768-OQW-145/images/the-d... for more information if you're curious.