I think you are not aware of the context here. The reason they have a wifi expert roaming around is because they are marking free wifi spots as part of streetview.
To mark hotspots you don't need packet sniffing or data capture of any kind. Why is Google capturing packet payload during "wardriving"? Nobody does that. All you do is store the GPS location, plus basic AP identification, period.
To mark hotspots you don't need packet sniffing or data capture of any kind. Why is Google capturing packet payload during "wardriving"? Nobody does that. All you do is store the GPS location, plus basic AP identification, period.