Allen Very Serious Versfeld on Nostr: Oh I'm sure it's doable - build a sensitive enough receiver with the right antenna ...

Oh I'm sure it's doable - build a sensitive enough receiver with the right antenna and you can do amazing things. But can you take that equipment out of the laboratory and miniaturize it enough to be able to use it in public at a till without attracting suspicion? If it was 50 meters then you could hide it in your car in the parking lot, but 2 meters is close enough that you need to disguise it as a phone or something.