A note for folks that'll be downtown #Denver (and likely elsewhere) for the #nokings event today: turning on airplane mode on your phone is _not sufficient_ to prevent tracking.
I haven't spent time on 16th St since it reopened, but recall the electronic billboards there previously were packed to the gills with bluetooth/wifi MAC trackers, ostensibly to track ad impressions.
You need to turn off all your phone radios: cellular, wifi, and Bluetooth.