Trust, therefore, need not carry the whole burden of cooperation (otherwise, it would fail in Oslo as in Naples). But neither is policing sufficient by itself. Policing relies on the existence of sufficient trust so that drivers need not feel obliged to monitor every call they lose, and enough demand to keep them busy, profitably diverting them from the temptation to spy on their colleagues.

Diego Gambetta, The Sicilian Mafia The Busi…, loc. 599