1. A computer-readable medium having computer-executable instructions stored thereon in a local computer system connected to a computer network, said instructions configured to perform a method comprising the steps of: (a) obtaining a request to identify specified data objects in accordance with a criterion; (b) determining the specified data objects that are stored on the local computer system and that correspond to a local identification set of the specified data objects; (c) querying a first computer system in the computer network for the specified data objects that are not stored on the local computer; (d) obtaining a first identification set of the specified data objects that are stored at the first computer system; and (e) merging the local identification set and the first identification set to form a merged identification set.