8. A computer readable storage medium containing an executable program for testing a sub-ontology for safeness, the sub-ontology comprising one or more elements of a given ontology, the elements comprising one or more individuals that represent at least one person or object, one or more relationships defined between the one or more individuals, and one or more pieces of metadata representing at least one characteristic of the one or more individuals and the one or more relationships, where the program performs the steps of: defining a first subset of the one or more relationships, the first subset comprising all sensitive relationships in the given ontology; defining a second subset of the one or more relationships, the second subset comprising the sub-ontology; and determining whether any relationship in the first subset can be inferred from any relationship in the second subset, given one or more inference rules.
8. A computer readable storage medium containing an executable program for testing a sub-ontology for safeness, the sub-ontology comprising one or more elements of a given ontology, the elements comprising one or more individuals that represent at least one person or object, one or more relationships defined between the one or more individuals, and one or more pieces of metadata representing at least one characteristic of the one or more individuals and the one or more relationships, where the program performs the steps of: defining a first subset of the one or more relationships, the first subset comprising all sensitive relationships in the given ontology; defining a second subset of the one or more relationships, the second subset comprising the sub-ontology; and determining whether any relationship in the first subset can be inferred from any relationship in the second subset, given one or more inference rules. 9. The computer readable storage medium of claim 8 , wherein the determining comprises: building a closure of the second subset; and determining whether the closure of the second subset intersects with the first subset.