StigmergicSystems work like this : one ant leaves cues in the environment which another, independent agent, picks up on and follows.
When JohnRobb applies the term "stigmergic" to the BazaarOfViolence in Iraq he means that one group sees media reports of an attack of a certain kind (kidnapping, blowing up oil infrastructure) and decides to copy it. Hence similar behavior is spread without any direct causal connection. Groups 1 & 2 are not instructed by the same leaders or connected in any way except through the media environment.
:seems eerily like a passage in RobertCialdini's Influence on suicides inspired by plane crashes (or was it the other way round?), bizarre - kk
Guerrillas enjoy public communication : http://globalguerrillas.typepad.com/globalguerrillas/