Blue Shield of California Confirms MOVEit Data Breach at MESVision Compromised Consumers’ Confidential Information | JD Supra. On November 17, 2023, California Physicians’ Service dba Blue Shield of California (“Blue California”) filed a notice of data breach with the Attorney. If you received a letter from Blue Shield of California discussing a vendor data breach, it is essential you understand what is at risk and what you can do about it. A data breach lawyer can help you learn more about how to protect yourself from becoming a victim of fraud or identity theft, as well as discuss your legal options following the Blue California vendor data breach. For more information, please see our recent piece on the topic here. Third-party company: Medical Eye Services, Inc..