The real benefit inspired by the authors might be in a logging scheme for moving in surveilled spaces. When I pass through a bounded space, my tracker app gets a log of the camera whose space I moved through. If you wanted to request the footage you’d have a 2-party confirmed list of cameras and times to request, reducing impact of a request and potentially increasing East of compliance.

This would be difficult still without fine-detail geographic bounding via maybe Bluetooth and likely very expensive to retrofit into existing systems, but would also still protect other private individuals’ privacy and security. Released footage could still be masked, for example, and access and use encouraged to be more directly audited.