1. A method performed on at least one computing device, the method comprising: obtaining identity information that includes a set of identities, where the identities in the set corresponds to an application with a degree of specificity; ranking the identities in the set of identities by relevance, where the relevance of each identity in the set is based on the degree of specificity of the each identity to the application; determining a reputation for each identity in the ranked set of identities that is known to a reputation service provider; and determining a reputation of the application based on at least some of the determined reputations of the known identities, and further based on at least some of the relevances of the identities.