1. A computer-implemented method comprising: receiving, at a social networking system, metadata associated with an object maintained by the social networking system; determining an amount of metadata previously received from the user and associated with one or more objects maintained by the social networking system; retrieving information associated with the user by the social networking system if the social networking system has previously received less than the threshold amount of metadata for association associated with one or more objects maintained by the social networking system from the user; calculating a confidence value associated with the user based on characteristics of the user determined from the information associated with the user if the social networking system has previously received less than the threshold amount of metadata for association associated with one or more objects maintained by the social networking system from the user; and storing the metadata without associating the metadata with the object if the confidence value associated with the user is less than a threshold value.