So I want to show off my brand new LED 55″ flat screen TV that is hanging off my living room wall. I get my iPhone and snap a picture. I then proceed to email just about everyone I can, including those who aren’t really that close to me. Well, unwillingly I just told every single person who I just emailed where I live.
How is this possible? With the magic of geotagging. What is Geotagging? Geotagging is adding gps data to various types of media, images, video or websites. In my case, when I took the picture of my TV, the iPhone’s Location Services added the gps coordinates of my location (my home) to the image. Since that information was stored on the image, anyone with the proper knowledge can figure out exactly where I took the image and even plot it on a map. Thus knowing where I live!
In the scenario I gave it was just a TV, however say you take pictures of your kids at school. You can imagine the implications of this as there are some not-so-nice people in the world. Technology can aid us but it can also hurt us. More importantly, we need to know how it can hurt us to prevent it from doing so in the first place.
Location Services Prompt
Without getting too technical, ever since the iPhone 2.0 software (iPhone 3G and 3GS) Apple has added system wide Geotagging capabilities. Although the company policy is to require apps to prompt you before using the capabilities, unfortunately after you click on “OK” twice-in-a-row the settings default to always allow the application to use Location Services. Sometimes we’re in a hurry and the iPhone being the native multi-touch that it is, we can easily forget that we already clicked “OK” twice-in-a-row.
How do I turn off Location Services?
Luckily it is quite easy to disable Location Services on the iPhone. All you need to go is touch Settings–>General–>Location Services and switch to off.
Settings
Now if you want to keep Location Services on for certain applications or instances, you can still force applications to prompt you by resetting Location Warnings. To reset simply scroll all they way to the bottom of the setting screen and touch Reset Location Warnings–>Reset Warnings.
Reset Settings
Now when you launch applications like the Camera or Maps the interface will prompt you once again on allowing Location Services. Just remember that once you click on “OK” twice-in-a-row, the iPhone will assume its ok to use your location.
Take into account that there are various devices that have geotagging capabilities like SLR Digital Cameras and Smart Phones. You’ll have to consult with the manual or do an online search for those devices’ settings.
I already uploaded my images to Facebook before turning off those settings, now what?
Once again you’re in luck! Facebook actually removes any EXIF data (where the geotagging information is stored) via the various scripts that your image goes through and compression processes. Don’t believe me, you can read it yourself here on Facebook’s own blog.
Image site services like Photobucket and Flickr are a different story since they do keep the EXIF metadata containing your possible geotagging info. Always use caution when posting online. There probably isn’t any danger and this post is just over-cautious, but it is always better to know exactly what is going on.
For peace of mind here is an add-on for firefox that allows you to read EXIF data from images called FxIF:
http://christian-eyrich.de/mozilla/fxif/