This policy memo was submitted to the United Nations High Commissioner of Human Rights in September 2015, in response to a call for consultations on the international challenge of how to create and maintain civil society space.  The authors review the commercial colonization of public space, particularly in schools, and discuss how the city of Sao Paulo's experience with its "Clean City Law" demonstrates both how unrestrained commercial communication constrains the public sphere and how that constraint may be effectively removed. They recommend a parallel policy banning commercial communication in schools, in order to provide students with the space in which to consider visions for themselves other than as consumers and to contemplate social and cultural values that have no commercial purpose.