With no other information, you probably can't. But imagine the metadata as a graph; phone numbers are nodes, edge weights correspond to the length and frequenc

With no other information, you probably can't. But imagine the metadata as a graph; phone numbers are nodes, edge weights correspond to the length and frequency of calls between the two phone numbers. Clique (http://en.wikipedia.org/wiki/Clique_(graph_theory) http://en.wikipedia.org/wiki/Clique_(graph_theory)) -like entities in that graph are people who are all in close communication, so if you know that one phone number is a suspected xyz, the others in the clique are probably of interest too.