A method of updating a database (211) comprising a fingerprint of and an associated set of metadata for each of a number of multimedia objects, A multimedia object and a set of metadata for the multimedia object is downloaded from a file sharing client (101-105). A fingerprint is computed from the multimedia object, and the computed fingerprint and the obtained set of metadata are included in the database (211). The database (211) can be maintained by a central server (210), or be maintained in a distributed fashion by servers (404) running on the file sharing clients (101-105). The database (211) in this way accumulates plural sets of metadata associated with one particular fingerprint. When a sufficient number of sets has been collected, a definite set can be determined using filtering techniques.