Should be relatively easy to "flood the zone" with tons of fake MACs as you walk by. Once they realize 100 million people did not really visit that sign, they might reconsider.
An enterprising person could probably design a casing for a solar powered Pi and stick it to the top of the kiosk.
Or just set up your own recorder at each sign and replay the last week’s traffic in random order.
Reminds me of the guy who created rolling traffic jams on google maps by pushing around a wheelbarrow full of phones.
I was wondering that too. Instead of having to guard my phone's settings all the time to prevent leaking data, I'd rather poison the well. It would be interesting to see if you can use a Flipper Zero to flood these devices with fake or corrupted data (and perhaps cause some interesting side effects).
Flipper Zero doesnt have wifi (though there are external solutions).
Probably easier to do what you describe with a laptop or smartphone.