Even with strong administrative safeguards and comprehensive firewalls , a health data breach can occur if employees at an organization are careless with computers and portable devices that store sensitive information . Visionworks , a subsidiary of Pennsylvania - based health insurer Highmark Inc. , is learning that lesson as it faces a potential data breach after a computer server went missing from an Annapolis store . The server was replaced on June 2 , 2014 during schedule upgrades , according to a Visionworks statement . However , it is believed that the server was sent to one of the stores landfills along with other miscellaneous refuse . The server potentially held partially unencrypted protected health information ( PHI ) belonging to as many as 75,000 customers , the statement read . Customer credit card information that was stored on the server was encrypted , Visionworks said , and therefore should not be at risk . Moreover , Social Security numbers were not included in the server . The company is currently in the process of notifying customers potentially affected and offering them free credit monitoring , Lisa Martinelli , the chief privacy officer for Highmark Health , told PennLive . The server in question was replaced during a store remodeling that began in June , Martinelli said . The device was reportedly being stored at the location , but when Visionworks recently initiated a recall of the server to have its data erase , it was found to be missing . However , Martinelli added that there is low probability of harm resulting from the loss . ;