How are Foursquare and Yelp collecting wifi scans? -> ok so yelp bought "Turnstyle WiFi" which runs wifi hotspots at businesses like Burger King and collects c

How are Foursquare and Yelp collecting wifi scans? -> ok so yelp bought "Turnstyle WiFi" which runs wifi hotspots at businesses like Burger King and collects client data ...keeps reading... oh god their wifi is worse than their burgers this is sickening