4. A computer-implemented method, comprising: obtaining a set of search results responsive to a search input from a first user; determining, from the search results and based on a social graph, that a first search result associated with a second user is indicated as keeping an identity of the second user hidden, wherein the social graph is identified or generated based on a source having contact information associated with the first user; determining whether other search results in the set are indicated as keeping respective identities of associated other users hidden; calculating a score for the first search result based at least on the determinations, the score indicating the likelihood of the first user guessing the identity of the second user; and determining, based at least on the score, whether to provide the first search result to the first user, wherein for the associated other users keeping the respective identities hidden, the score is based on a product of a number of the associated other users keeping the respective identities hidden and a sum of distances between each of the associated other users keeping the respective identities hidden, the associated users being on the social graph, and for the associated other users permitting sharing their identities, the likelihood is based on a multiple of a threshold value.
4. A computer-implemented method, comprising: obtaining a set of search results responsive to a search input from a first user; determining, from the search results and based on a social graph, that a first search result associated with a second user is indicated as keeping an identity of the second user hidden, wherein the social graph is identified or generated based on a source having contact information associated with the first user; determining whether other search results in the set are indicated as keeping respective identities of associated other users hidden; calculating a score for the first search result based at least on the determinations, the score indicating the likelihood of the first user guessing the identity of the second user; and determining, based at least on the score, whether to provide the first search result to the first user, wherein for the associated other users keeping the respective identities hidden, the score is based on a product of a number of the associated other users keeping the respective identities hidden and a sum of distances between each of the associated other users keeping the respective identities hidden, the associated users being on the social graph, and for the associated other users permitting sharing their identities, the likelihood is based on a multiple of a threshold value. 8. The method of claim 4 , wherein the determining whether to provide to the first user the first search result is further based on another input from the first user.