This paper challenges the ideas beyond the application of smart technology in the urban environment by investigating the proposal for the waterfront of Toronto by Sidewalk Labs. Although the project has been cancelled in the first months of the COVID pandemic outbreak, it still offers a valuable case study, as it was developed by Sidewalk Labs, part of Alphabet Inc, the company behind, among others, Google. This paper focusses on the spatial, material, and political aspects of the proposal, which are (...) investigated through an architectural reading of Hannah Arendt’s notion of the world. The paper reflects on the public spaces in the plan, and in particular to the ambition to make these spaces “responsive” to popular demand. This ideal is inherent to the most far-fledged convictions beyond smart cities. In contradiction to its promising images and wild ideas, this paper concludes that it silences the participants and diminishes the possibility of active participation in the built environment. (shrink)