From Wikipedia
The term “sousveillance” stems from the contrasting French words sur, meaning “above”, and sous, meaning “below”, i.e. “surveillance” denotes the “eye-in-the-sky” watching from above, whereas “sousveillance” denotes bringing the camera or other means of observation down to human level, either physically (mounting cameras on people rather than on buildings), or hierarchically (ordinary people doing the watching, rather than higher authorities or architectures doing the watching).
