Playing devil's advocate a little, the value in the data from an intelligence perspective is probably in the network it uncovers. If you know a circle of people

Playing devil's advocate a little, the value in the data from an intelligence perspective is probably in the network it uncovers. If you know a circle of people are regularly exchanging encrypted messages, then you can try to target one member and get them to compromise the group by turning them into an informant. Similarly, if you suspect someone, you can look at their records to discover the networks of potential conspirators, then fan-out for each member until you have a big picture of interactions between different networks. There's a great example of exploiting simple person-person interaction graphs to generate this information here: http://kieranhealy.org/blog/archives/2013/06/09/using-metadata-to-find-paul-revere http://kieranhealy.org/blog/archives/2013/06/09/using-metada...