In the North as in the South, we like the big cities, but we do not like violence. A fashionable exercice is to allocate reasons to the poorest inhabitants, then to adopt, to fight them, security strategies: our societies are quickly transformed into societies of fear. Urban planning, already, divides the space into fortresses and shanty towns. But we cannot continue thinking of urbanization since police stations:an alternative reading of the phenomena of urban violence and insecurity is necessary. It can only be done by re-locating them in the context the violence the urbanization and globalization. By taking into account, also, the point of view of the poor people, "villains", outsiders, illegal, robbers, gangs. Therefore, it is necessary to re-learn the city with the gangs of shanty towns. When everything seems closed, the « vision of the poor man » opens new solutions for a pacification of the urban territories. Against actual security obsession, we advocate an inventive dialogue with those the Power demonizes. This book should be so a sort of "guidebook" for the inhabitants of the big city, those that it scares as those who like it and do not want to abandon it, even if they are poor and "bad", even if the city destroys them more than it protects them. To rebuild habitable cities, it is necessary to disobey models.