The City of Grass Valley experienced unauthorized access to its computer systems between April 13, 2021, and July 1, 2021. The attacker exfiltrated files containing names, Social Security numbers, driver's license numbers, financial account and payment card information, and limited medical/health insurance data for employees, vendors, and residents. The City notified law enforcement, engaged a cybersecurity firm, and began notifying affected individuals on January 7, 2022, offering one year of Experian IdentityWorks.