German artist Simon Weckert shows how he can create fake traffic jams in Google Maps by walking around the streets of Berlin with 99 cell phones. Google Maps utilizes GPS and location data from mobile devices to determine if there is traffic congestion on a particular street. The app will then redirect users to less trafficked streets to avoid traffic. This could also have security ramifications as threat actors can use this type of data manipulation to reroute cars down specifically chosen routes rather than ones defined by valid traffic data.
Source: https://www.bleepingcomputer.com/news/software/hack-creates-fake-google-maps-traffic-jams-with-99-cell-phones/