There’s a lot of research being directed towards creating systems which can automatically detect ‘suspicious’ behaviour within public spaces. In particular, it’s possible robustly to detect someone who is ‘loitering’ -any object of a certain size which appears in a succession of video frames at slightly different locations is considered worthy of investigation.
Today’s invention is to link this video analytic technique with a highly-directional loudspeaker. Once someone has been found to be hanging about, a recorded verbal message would be sent to them (so that no-one else could hear).
This would probably take the form of a request to show some identification to the camera. This would then allow it to zoom in and automatically extract some further information from the text.
Failure to respond appropriately to this unexpected challenge might result in the system issuing an alert to a human operative to investigate further.