Probabilistic aspects of a mobile service scenario.

The mobile Internet offers services that e.g. receive the location of the nearest point of interest such as a store, restaurant, or tourist attraction. Consider a user and data points corresponding to the locations of e.g. stores. In order to preserve some privacy, suppose the user queries a server for nearby points but he reports not his correct location but another location referred to as the anchor, where the data points are ordered in increasing distance to the anchor. The user then stops to query the server as soon as he has determined the nearest data point (with respect to q).
The challenge addressed is how to obtain the best possible performance, subjected to given requirements for location privacy and query accuracy.