Facial recognition would be able to detect all the strangers around you, whereas audio would surely only pick up people nearer the device, and presumably wouldn't be able to tell people apart/identify them. You're right about network data; if they're using Wifi/BT probes then they can already find and identify everyone in the vicinity.I'm curious why you're using past tense by the way?
manveerc|14 days ago
And with respect to past tense, I don’t know if they still do when they were caught red handed about some of these things. Unless there is a court order I am sure they still do, but I have no proof point.