Over the past decade, security has gained enormous attention in the urban literature, reflecting its visibly increasing presence in cities worldwide. It is now widely acknowledged that security is a structuring force for cities both historically and now. Few scholars have however looked at the implications of security on the daily practices of urban dwellers. Based on extensive fieldwork during which we developed a street by street survey of security mechanisms in Beirut (Lebanon), interviewed city dwellers, and worked with artists and local writers reflecting of “security issues”, this paper describes “security” as the accumulation of a set of constructed threats that bring together a multiplicity of forms and agents of securitization, both public and private, and generate new forms of social hierarchies with unequal repercussions on city dwellers. Far from the coherent symbol of an independent sovereign, we argue that security acts in Beirut as a reflection of and a catalyst for social and political divisions.