As location tracking capabilities of mobile devices are increasing, problems related to user privacy arise, since user's position and preferences constitute personal information and improper use of them violates user's privacy. Several methods to protect user's privacy when using location based services have been proposed, including the use of anonymizing servers, blurring of information e.a. Methods to quantify privacy have also been proposed, to be able to calculate the equilibrium between the benefit of providing accurate location information and the drawbacks of risking personal privacy.Users of such services may also choose to display more generic location information (i.e. "In the City" or "Philadelphia" or "Work") to some of their more casual acquaintances while only displaying specific location information, such as their exact address, to closer contacts like spouse, relatives, and good friends.

Source: Wikipedia