Uncertainty is the mechanism

Fixed cameras produce a known condition. A sign, a housing on a wall, a place you can point at. People adjust once and stop thinking about it, which is why CCTV became socially digestible even at high density.

Worn cameras produce something different. You cannot tell whether one is present, so the only consistent posture is to behave as though one might be, everywhere, permanently. That is not a decision anyone makes deliberately. It shows up as slightly less said in a waiting room, a conversation moved outside, a hand raised at a meeting a beat later than it would have been. Open Rights Group has been arguing that recent changes to the UK data protection regime leave biometric information more exposed than it was, a concern it set out in its work on the direction of UK data policy, and the behavioural side of that exposure gets far less attention than the legal side.

Our own numbers cut both ways

We should be careful here, because the honest reading of our field data does not support alarm about density. At one arena, in a crowd of roughly seven thousand, we logged fifteen detections. At a theatre, none among 823 devices in range.

Which raises an uncomfortable possibility. If people are already adjusting their behaviour in public, and the actual prevalence is this low, then the cost of the perception currently exceeds the cost of the capture. Anyone campaigning in this area, ourselves included, should sit with that. Overstating presence produces the chilling effect without the surveillance, which is the worst available outcome.

A trustworthy negative is a civil liberties good

This reframes what a detection tool is for. The valuable output is not the alert. It is the reassurance, and specifically a reliable statement that nothing compatible is nearby, which is precisely the statement the radio cannot support.

That limitation is the whole problem, and it is not solvable by better software. Until a device that captures is required to announce itself in a form anything can read, no tool can give you an honest all-clear, and the ambient uncertainty stays exactly where it is.