1. A face image tracking system for a site, comprising: a storage unit storing face images of persons that were acquired when the persons visited the site; an imaging unit configured to capture a face image of a person when the person requests deletion of a face image of the person stored in the storage unit; and a processing unit configured to extract one or more stored face images that have at least a threshold similarity to the face image of the person captured by the imaging unit, and delete one of the extracted face images from the storage unit.