efore you proudly go posting photos of your Ming vase online, you should be aware that computer-savvy burglars can likely use that photo to find out where you live. The same goes for photos or videos of your kids, yourself, or anything else that you don’t want strangers knowing how to locate. The practice of tracking people via their posted images is an example of “cybercasing”, and is possible because many digital cameras and smart phones, including the iPhone, automatically geotag their images by embedding the longitude and latitude at which they were taken. Even when uploaded to a website, the images still retain this information. By plugging the coordinates into a service like Google Street View, getting an address or an identifying landmark is entirely possible. This disturbing fact was recently announced in a report published by the International Computer Science Institute (ICSI). Researchers Gerald Friedland and Robin Sommer wrote that they successfully obtained the home addresses of people who had posted photos in ads on Craigslist, despite those people having opted to keep their addresses hidden in their postings. Creepier still, they were also able to obtain addresses where home videos of children had been shot, by searching under the tag “kids” on YouTube. They then proceeded to search for recent videos from those same users, that had been shot over 1,000 miles away. Within 15 minutes, they were able to determine that 13 of these video posters were likely still away on vacation, leaving their homes available for burglary. While iPhones do geotag by default, it is possible to turn the feature off. The folks over at I Can Stalk U (they’re against stalking, not in favor of it) can show you how. For other phones and cameras, a Googling or a look through your user’s manual should tell you what you need to know.
In short, metadata is more data about data. In most common document types, embedded within a file is more information, typically hidden from casual viewing. This hidden data is used by the computer programs to provide accurate processing information, i.e. what version of software was used to create the document, how the file is encoded, and often who created it. In the case with many popular image/picture formats, the list of possible metadata is quite extensive. With the expanded options for metadata in JPEG images, we have the ability to record the photographer, camera settings (ISO, Aperture, Flash, lens type), processing software and location. The metadata in images is often retained by default by desktop image processing software and many online photo storage websites. This information is often valuable to the photographer, as well as the website provider for demographic information. Of course, location is also one of the options available for storage in a JPEG image. The storage of location based data, in the form of Latitude and Longitude inside of images is called Geotagging; essentially tagging you photograph with the geographic location. This data is stored inside if the metadata if JPEG images and is useful for tying the photograph to a location. Want to remember exactly where you took those photographs while on vacation? This information is for you. However, most modern digital cameras do not automatically add geolocation (Latitude and Longitude) metadata to pictures. The process for adding the geolocation data either requires specialized add on hardware, or post processing with software on the desktop after the pictures are taken. There is a large exception to this rule: Smartphones. With the proliferation of smart phones that contain GPS locator technology inside, the cameras in these devices are already equipped with the specialized hardware to automatically add geolocation information to the pictures at the time they are taken. Most people don’t realize that the action of automatic geotagging takes place on their smart phones, either because it is enabled by default, not exposed the user as an option, or was asked and then forgotten. As a result, individuals often share too much information about their location, right down to the exact Latitude and Longitude when snapping photos with their smartpphone and posting them online. How do I disable this? The easiest way to stop posting this information for all to see it to disable geotagging on your smartphone. Disabling on your phone: There are many phones out there on the market that geo tag their pictures and as we get more information, we will update the instructions to list more models, however, lets see how to do that with the Apple iPhone: With the iPhone there are two ways to disable Geotagging of photos. The first involves disabling of all location based services. To disable this feature, Go to Settings, General then set Location Services to off.
Be warned: This will turn off ALL location based services for ALL applications. Of course we may actually have need to use location based services for other applications (such as maps and driving directions, or getting robbed via Foursquare), but just not for our pictures. There is no easy way to disable location based servces for jsut one application. However, we can make the iPhone prompt us at first use for each application. Once reset, the first time we enter the application we can enable or disable location based services for the application. To do so we need to go to Settings, General, Reset.
Be careful here! We want to select Reset Location Warnings, and then Reset Warnings. This restores all of our Location based warnings for each application to the default, which in most cases is “Ask on first use”. From here, once we enter into the default Camera app on the iPhone, we can select Don’t Allow. This will prevent the Camera app from geotagging our photos.