In just a few years, Smart Cities have become the object of all expectations. Smart Cities, supposedly improving the urban lifestyle while making the use of resources required for various urban activities more efficient, are based on a blind belief in the neutrality of the technological systems that structure them. However, the neutrality of the urban data collection and analysis technological systems is not self-evident, and raises the question: what relationship (s) with reality do they establish? What true freedom do they leave to the inhabitants? How is control and surveillance of the human activities they bring about to be interpreted? Through a firmly critical approach to Smart Cities, the objective of this article is precisely to answer these questions while enlisting the conceptual frameworks of the works by Heidegger and Foucault. By enlisting these two theoretical frameworks, two main characteristics of Smart Cities are highlighted and analysed. According to a Heideggerian approach, Smart Cities appear to be an organisational phenomenon, pertaining to enframing of reality where the existence of city-dwellers becomes a resource to be used and controlled in the same way as other resources. According to a Foucauldian approach, they are revealed to be a managerial phenomenon where disciplinary power is expressed across the various urban activities via technological systems.