A platform that facilities preservation of user privacy with respect to location-based applications executing on mobile computing devices is described. The platform registers triggers that are set forth by location-based applications, where a trigger specifies one or more rules and includes a location constraint. The platform causes a sensor on the mobile computing device to output location data, and the platform determines if the trigger has been satisfied by comparing the location constraint with the location data. If the trigger is satisfied, the platform transmits a callback to the application. Accordingly, the application does not receive location data from the sensor.