GRAPHDATABASES seem to be tailor-made for NETWORKING applications. The prototypical example is a social network, where nodes represent users who have various kinds of relationships to each other. Modeling this kind of data using any of the other styles is often a tough fit, but a graph database would accept it with relish.
They are also PERFECT matches for an object-oriented SYSTEM.
Cons
Because of the high degree of interconnectedness between nodes, graph databases are generally not suitable for network partitioning.