Web Photo Geotags Can Reveal More Than You Wish

When Adam Savage, host of the popular science program “MythBusters,” posted a picture on Twitter of his automobile parked in front of his house, he let his fans know much more than that he drove a Toyota Land Cruiser.

Embedded in the image was a geotag, a bit of data providing the longitude and latitude of where the photo was taken. Hence, he revealed exactly where he lived. And since the accompanying text was “Now it’s off to work,” potential thieves knew he would not be at home.

Security experts and privacy advocates have recently begun warning about the potential dangers of geotags, which are embedded in photos and videos taken with GPS-equipped smartphones and digital cameras. Because the location data is not visible to the casual viewer, the concern is that many people may not realize it is there; and they could be compromising their privacy, if not their safety, when they post geotagged media online.

Mr. Savage said he knew about geotags. (He should, as host of a show popular with technology followers.) But he said he had neglected to disable the function on his iPhone before taking the picture and uploading it to Twitter.

“I guess it was a lack of concern because I’m not nearly famous enough to be stalked,” he said, “and if I am, I want a raise.”

Still, Mr. Savage has since turned off the geotag feature on his iPhone, and he isn’t worried about the archived photo on Twitter because he has moved to a new residence.

But others may not be so technologically informed or so blasé about their privacy. ...

By downloading free browser plug-ins like the Exif Viewer for Firefox (addons.mozilla.org/en-US/firefox/addon/3905/) or Opanda IExif for Internet Explorer (opanda.com/en/iexif/), anyone can pinpoint the location where the photo was taken and create a Google map....

... The Web site ICanStalkU.com provides step-by-step instructions for disabling the photo geotagging function on iPhone, BlackBerry, Android and Palm devices.

via Web Photo Geotags Can Reveal More Than You Wish - NYTimes.com.

Here is an example of what someone could see if you leave geoTagging on and post a picture taken with your iPhone. You will know exactly which model of iPhone, the location, time to the second, date, even firmware version the person is using.

# Camera Make = Apple
# Camera Model = iPhone 3GS
# X-Resolution = 72/1 ===> 72
# Y-Resolution = 72/1 ===> 72
# X/Y-Resolution Unit = inch (2)
# Software / Firmware Version = 3.1.2
# Last Modified Date/Time = 2009:11:26 00:33:52
# Y/Cb/Cr Positioning (Subsampling) = centered / center of pixel array (1)
# Exposure Mode = auto exposure (0)
# White Balance = auto (0)
# Sharpness = soft (1)

# GPS Latitude Reference = N;óñ
# GPS Latitude = 36/1,2757/100,0/1 [degrees, minutes, seconds] ===> 36° 27.57′ == 36.4595°
# GPS Longitude Reference = W;lÇ
# GPS Longitude = 117/1,5069/100,0/1 [degrees, minutes, seconds] ===> 117° 50.69′ == 117.844833°
# Links to online mapping websites:

* Google™ Maps
* Yahoo!® Maps
* MSN® Maps & Directions
* Mapquest®
* Open KML data with Google™ Earth
* Save KML data to file
* Save KML data to file and open with Google™ Earth

# GPS Altitude Reference = sea level reference (negative value)
# GPS Altitude = 1066/1 m ===> 1066 m
# GPS Time Stamp / UTC Time = 0/1,33/1,5447/100 [hours, minutes, seconds] ===> 0h 33m 54.47s
# GPS Image Direction Reference = (null)
# GPS Image Direction = 25168/177 degrees

How to turn off geotags on your iPhone. If you have the latest version, it is even better than the directions above because you can Go to Settings, General, Location Services and then turn off location determination for your camera only. Or for Google, or for maps separately.

Test your own photos to be sure you've turned off your tags.

Any recommendations for an open source bulk scrubber to remove all tags from past images you've saved?