With all the location-based social media applications out there, it’s only logical that, in addition to being able to restrict access based on ones social groups (or circles), that geographic boundaries also be used as a restrictive parameter. That capability is called a geofence, a virtual way to set the geographic boundaries that a user wants to fence off for privacy reasons or to trigger a specific action.
Flickr recently made news with the introduction of its geofence privacy feature (via @kjphotography). Users can draw circles on a map to delineate the geographic area they want to create viewing restrictions for certain geotagged photos. Once a geofenced area is delineated, specific users can be flagged with permissions to view those photos. Up to ten geofenced areas can be drawn. The Flickr blog has more details about the brainstorming that led to this new geofence feature and specifics about the feature itself (and if you want to get into more of the nitty gritty of Flickr’s geofencing, there is a followup post). Once a geofence is set up, the privacy settings are retroactively applied to all geotagged photos within the restricted area. The feature is a great way to mask a user’s home location or to prevent sensitive locations such as a child’s school from being revealed through inadvertent geotagging.
Geofencing has other applications in addition to privacy purposes. Geofencing can also be applied to notify users when their geographic location meets certain criteria. Geofencing commonly is used for notifications when a user enters or leaves a designated area, such as tracking a parolee via GPS who has to remain within a specific area. An example of a commercial application would be a user searching for new homes. When the user (along with his or her GPS enabled smartphone) is within a specified range of a house for sale that meets predefined criteria, the user would then be notified of the house location and its details on that same smartphone. Location Labs, which develops geofencing software, has partnered with aisle411, a mobile retail navigation service to create a notification system that alerts shoppers of deals when they enter a store as part of the aisle411 system.
