Your daughter has just been in a car crash. She falls unconscious on her way to the hospital, but not before she is able to tell the paramedics the name of her doctor. This is vitally important because the emergency room wont know that shes an insulin-dependent diabetic with a penicillin allergy, but her doctor will be able to give them her relevant medical history.
Or, at least he would be if hed renewed the tech support contract on his medical records software. He didnt, though, and now his information and your daughter is locked away in a proprietary database he cant access.