How Exif Data in Your Photos Impacts Your Privacy

When is a picture worth more than a thousand words?  When it contains hidden data that is transferred within the picture file you just emailed unsecurely or shared with the world on Google+.  Exif, which stands for exchangeable image file format, is a standard that specifies the formats for images, sound, and ancillary tags used by digital cameras (including smartphones), scanners and other systems handling image and sound files recorded by digital cameras.

Exif data contains a number of metadata tags about the photo such as the date and time it was taken, make and model of the camera, various camera settings and other information including GPS information.  The GPS information is the most disturbing part from a privacy perspective.  If you take a photo inside your home and upload it to Google+ someone trying to dox you can instantly determine where you live by simply looking at the GPS coordinates embedded in the photo you uploaded.  Not all cameras record GPS data and some cameras record more exif data than others, but all modern cameras record at least some exif data with each photo taken.  This data follows your photo around, unless you actively take steps to remove it before the photo is uploaded to the internet.

Various social media sites treat exif data differently.  Facebook resizes and compresses photos uploaded to its servers and removes some of the associated exif data.  So does Twitter.  Google+ on the other hand, leaves all of the exif data intact and available for viewing by anyone who has access.

Here is a sample photo I found on the internet that contains a substantial amount of exif data:

You can download this photo to your computer to examine the exif data or you can use various online tools.  If you download it to your computer, you can go to file manager, right click on the photo, select properties and click on the details tab.

If you are browsing the internet and you want to see the exif data without downloading the photo, you can go to a number of online sites, like exifdata.com, which will analyze the photo for you and report the exif data.

If you right click on the photo you want to research and select 'Copy Link Address' or 'Copy Image URL' you can paste it into the 'Submit an image URL' box here:

When we submit that URL, the site returns a significant amount of metadata information related to this photograph:

You can see the photo that was analyzed and some summary information, including where the photo was taken.  If you click on the 'detailed' button, there is even more information about this photo.

That photo you thought was just a picture of you and your family actually tells an entire story that cannot be seen by viewing the photo.

Next week, I will discuss how to remove exif data from your photos.