Mobile applications tracking wireless user location

Location-based services enabled by broadband wireless access play an increasingly important role in people's daily navigation and coordination. Location-based applications frequently report user location to Internet servers, and location accuracy is essential to the utility of these services. However, regular and accurate location updates impact efficient usage of network resources and also users' privacy, which is not directly observed by the users. In this paper, we conducted a large scale measurement study to understand location accuracy and communication frequency of such applications. We found that while most location reports are accurate enough, some applications run in the background, reporting user locations with a higher accuracy and frequency than needed for the user's purpose. For example, while from the user perspective, hourly zip code updates are enough location information to obtain local weather conditions, some weather forecast applications report user location every five minutes or less and at GPS-level accuracy. We found that location reports from many phone applications are accurate enough and frequent enough to enable the inference of users home and work addresses, and potentially their identity, exacerbating user privacy concerns.