Geotagging 101: When Invisible Data Reveals More Than The Image

Geotagging 101 -  When Invisible Data Reveals More Than The Image

Adam Savage of television’s Myth Busters learned about geotags the hard way. He inadvertently posted his home address to his thousands of Twitter followers.

That information, the GPS coordinates of where he stood when he snapped the picture with a camera phone, was embedded in the image file, which Internet surfers could easily see with the right software, such as the EXIF Viewer plug-in for Firefox.

iPhones, BlackBerrys, other smart phones and a host of higher-end digital cameras have the ability to “geotag” pictures and videos. It can be a convenient feature, but shouldn’t be your default setting if you regularly share photos online.

Different photo formats record different kinds of information within the picture, which we call metadata. This amounts to the “story” of the photograph and can include fields like date and time the picture was taken, exposure, camera type, file size and, ifit's GPS-enabled, location.

Metadata can be a huge help to professional photographers interested in just how they captured that particular photograph or to amateur photographers on vacation looking to immortalize that exact spot.

But there are moments in our life when we want a little more privacy. When we post photos of our home, or the car in our driveway, we could also be sharing where we live—and in some cases, when we are or aren’t at home.

Some sites, such as Facebook—and now Twitter following the Savage story—automatically delete or scramble metadata before posting, but to be safe, you should know your hardware.

If you have a camera with GPS your best bet is to read the manual. There is likely an easy setting for turning geotagging on and off. To learn how to toggle the feature on an iPhone, Android phone or BlackBerry, visit

To look at the metadata on your old photos, ExifTool is open source (free), and easy to use. Opanda is another good option for reading, writing and editing your metadata. You can quickly remove metadata from your image files, without affecting the image quality, with ExifTool, or JPEG & PNG Stripper.

Remember, awareness is the most important factor in safe computer and mobile usage. Know the real value of information before you release it to the public.

About Ondrej Krehel   |   Cybersecurity and Digital Forensics   |   LIFARS