[en] The cities are often shown as settings for significant social events, old and new, produced by altered citizens making insolent demonstrations, where the streets are used by aggressive expressions of protests and disorder. All these events are often called "alterations of the public order", organized by short-term social groups, which participate without knowing each other, only tied by the common aim of fighting against dominant powers in the city. When historians describe these events, they consider the city as passive settings where all these acts take place. On the contrary, it is seldom admitted to have a different view, taking into consideration a positive role of the morphology of the city, by selecting meaning and behaviors, and making inadmissible others, pushing in this way concrete actions and roles to the citizens. This argument is enough justification for a new branch of the urban ecology in order to explain, not only the history of these acts of revolt, but the role of the physical environment that is the base for these events, the background that, in fact, partially produces them. It is necessary, then, to analyze the concrete city forms and settings, the correlations between the moves of the protesters and the forms where these events take place. Also should be analyzed the order of these behaviors, and the space and time dimensions of the physical characteristics of the cities where these big or small occasional demonstrations are always exploding. We should, then, describe and analyze how these events use city places, how they ignore or find new meanings and uses, or show total insensitivity to their physical qualities. Then the city could be shown as a setting for conflictive behaviors, not as a place for calm, repetitive and easy to forecast, urban life, that is, an addition of behaviors far from any kind of confrontations. We know that urban landscapes can easily be converted into sites for revolt and disobedience.

[es] Las ciudades aparecen a menudo mostradas como escenarios de y para acontecimientos sociales importantes, presentes o pasados, cuyo protagonismo corresponde a fusiones de viandantes alterados que hacen un uso insolente de la calle o la plaza, convirtiéndola en campo para la expresión vehemente de disidencias o protestas. Se habla de revueltas, insurrecciones populares, revoluciones y, en un grado menor, de disturbios, enfrentamientos y algaradas, lo que el lenguaje legal denomina "alteraciones del orden público", siempre a cargo de coaliciones provisionales y efímeras de individuos casi siempre hasta entonces desconcidos entre si, que se apropian del espacio urbano para sus reclamaciones, haciéndolo frente o contra las instituciones dominantes en la sociedad en que viven. Cuando los cronistas del pasado o del presente muestran una ciudad asumiendo tal papel lo hacen de manera que éstas se pueden antojar meros decorados pasivos sobre los cuales se desarrollan las dramaturgias de la historia o la actualidad. En cambio, pocas veces se ha tomado conciencia del papel activo que las morfologías urbanas juegan en el desarrollo de estos hechos, de cómo se constituyen en parte activa de los acontecimientos, en la medida que estimulan o inhiben unos determinados estilos colectivos de actuar —al tiempo que hacen improcedentes o inviables otros— y ponen a disposición de los actores una red de funciones y significados que acaban determinando total o parcialmente el curso y las maneras de lo que ocurre o va a ocurrir.