In one embodiment, a method includes determining a pattern among a number of geo-locations of a user over a period of time. Each geo-location is determined and reported by a mobile computing device of the user without manual user input. The method also includes determining a particular geo-location among the geo-locations in the pattern with a minimum distance to a current geo-location of the mobile computing device; determining a distance between the particular geo-location and the current geo-location; and sending a notification of the current geo-location to one or more other users in response to the distance being longer than a pre-determined deviation threshold value. One or more of the other users have a relationship to the user based at least in part on social-graph information associated with the user.