Public spaces now depend on a neoliberal and entrepreneurial city that has to obey economic profitability priorities. This thesis aims at showing how municipalities try to bolster their image in order to attract new capital, which entails getting rid of its undesirables (the homeless and other people perceived as problems) who tarnish their public spaces’ image. This thesis includes three case studies : two malls The Grove and Americana At Brand, Business Improvement Districts and Safer Cities Initiative a zero tolerance policy program initiated by the city of Los Angeles in 2006. The goal is to understand to what extent the urban experience has been tempered and regulated with new codes, and in which all disturbing aspects have all been disolved in an urban fabric cleaned of all socio-cultural diversity. The automatic exclusion of undesirables embodies perfectly well this desire to impose dominant norms. All these new spaces seem safe and secured but they turn out to be controlled, surveilled, deprived of authenticity, in which bevahiours are heavily scrutinized. This thesis also aims to demonstrate how spatial and social exclusion mutually reinforce each other. Finally, it analyzes groups that are against public space privatization and offers alternatives to the redesign the contemporary city.