This document discusses the emergence of "sentient cities" enabled by ambient intelligence technologies like RFID, biometrics, sensors and ubiquitous computing. It analyzes three trajectories for these technologies: consumerization aimed at "frictionless capitalism", securitization and militarization for surveillance, and urban activism/art seeking to reclaim and reanimate public spaces. While commercial and security visions aim to make infrastructure transparent and anticipate human activity, an "oligopticon" of fragmented systems is more realistic. Art and activism offer alternative visions of enriched community and participatory urban experiences.