1. An information processing apparatus comprising: a processor coupled to a memory, the processor configured to: acquire one or more policies on disclosure of information on a target user, wherein at least one of the one or more policies includes a policy of prohibiting disclosure of a first attribute in combination with a second attribute; collect attributes related to the target user from public information disclosed on two or more networks to create two or more attribute sets related to the target user, wherein the two or more attribute sets include at least a first attribute set and a second attribute set, wherein the first attribute set derives attributes from a first network from the two or more networks, and wherein the second attribute set derives attributes from a second network from the two or more networks; analyze the two or more attribute sets to determine that the first attribute exists in the first attribute set and the second attribute exists in the second attribute set, wherein the first attribute does not exist in the second attribute set; determine at least one additional attribute disclosed on the two or more networks, wherein the at least one additional attribute exists in both the first attribute set and the second attribute set; calculating a score indicating a degree of difficulty in identifying the target user in association with an attribute included in the public information, wherein the score comprises a number of other users having a same attribute as the attribute included in the public information; and prohibiting disclosure of the first attribute and the second attribute responsive to determining the at least one additional attribute exists and a determination that the score is above a threshold value, wherein the prohibiting includes transmitting a request to remove the at least one additional attribute to a manager of the two or more networks, and wherein the threshold value is greater than zero.