- Goods purchased
- Amount paid for each
- Time and location of purchase
...about 40% to 70% of people always turn on Wi-Fi network interface of smartphones instead of turning it off for energy savings. Smartphones with Wi-Fi enabled periodically transit Wi-Fi probe messages, even when not connected to a Wi-Fi network. When smartphones detect and connect to Wi-Fi hotspots in the area of interest, the background programs and services of operating systems in the smartphones can generate large numbers of data transmissions, for example, Apple iOS message push notification service and Android message notification service. As Wi-Fi network interface in the smartphones has the unique MAC address, it is possible to identify the smartphone’s owner and distinguish his presence in the area of interest.
The authors go on to describe how this technology can be used (and in fact is being used )
The authors claim that the identity of the smartphone owners is hidden since only the MAC (a globally unique smartphone identification number) can be gleaned with this technology but not the phone number of the smartphone. This is re-identification 101 for someone to take the phone MAC address and convert it to the phone number or even directly to the smartphone owner.
By deploying Wi-Fi sniffer sensors in the area of interest, it is possible to capture Wi-Fi message transmissions without disturbing the normal daily use of smartphones, and to analyze the situation of humans stay and even the coarse-grained location traces of the smartphones from the big data prospective.
With the features of Wi-Fi sniffing, it can be widely used in the public places, for example, shopping mall, office buildings to analyze the dwelling of smartphones as well as the owners, even the features of human presence activities and classify varied user groups.
The icing on this cake is the big data techniques and tools can be easily used to completely unravel any shreds of privacy you thought you enjoyed by leaving your phone's Wi-Fi switched on in public.
So, next time you enter a mall in the new year, turning off your smartphone Wi-Fi may be a good idea including everyone with you. There are other ways they will still track you but at least not with your phone's Wi-Fi.
- International Journal of Distributed Sensor Networks Volume 2013, Article ID 927940, 12 pages, http://dx.doi.org/10.1155/2013/927940 - Discovering Human Presence Activities with Smartphones Using Nonintrusive Wi-Fi Sniffer Sensors: The Big Data Prospective