Luring and social engineering
Enemy tracking, a very difficult art, can be divided into stalking, reversing language patterns and luring. In order to stalk you need a deep knowledge of Usenet spamming (and war) techniques like flaming, trolling and crossposting. A good reverser can moreover easily 'reconstruct' (part of) the snailtrail of his enemies and defeat their smoke curtains applying some easy semantical reverse engineering tricks. Finally the reverser will lure his targets into the open web and identify it.
0) Some simple stalking tools
1) General stalking techniques
1.1) Simple email stalking techniques
2) Reversing language patterns
3) Luring and social engineering tricks