Thayer Academy reported a data security breach to the California Attorney General occurring on February 4, 2023. The notice indicates that personal information, including names and Social Security numbers, was potentially compromised. Affected individuals in multiple states, including California and Massachusetts, were offered 12 months of complimentary credit monitoring via Experian IdentityWorks. The specific cause of the breach and the number of affected individuals are not disclosed in the provided summary or attachment.