The other day, I posted 6 pictures on Twitter and challenged people to tell which pictures were of Arizona and which depicted the arid lands of North Central Washington. The correct answer came quickly from a lawyer in Chicago.  At first, I wasn’t sure how a resident of Chicago would recognize the local topography so well.   But later he admitted that he answered the question by downloading the pictures to his computer and examining the “metadata” of the photographs, which contained the GPS location and the longitude and latitude of my iPhone when I took the picture. The questions arose: what are the dangers of sharing your precise location on the internet?

Although there doesn’t seem to be any documented cases yet of criminals using geo-location, the subject has been discussed quite a bit online. Last month the U. C. Berkeley Computer Science Gazette discussed such a problem, and the writers discovered that quite a number of photographs of items for sale that were posted on Craigslist contained geo-tags. For those of you unfamiliar with geotagging, it is a digital camera feature that lets you embed GPS coordinates in a digital picture file to mark where it was taken.

An example of a view of a digital photograph's metadata or geotag showing the precise location of the camera when the image is taken

The concept is popular for vacation photographs because you can quickly identify precisely where the photograph was taken.  As you can see from the image at the right, the metadata of a digital photograph reveals quite a bit.  So in what ways might criminals take advantage of this feature?  What if you took a photograph of expensive jewelry and posted the pictures online?  Could a would-be burglar then examine the metadata to determine where exactly the jewelry was?  I suppose this is possible, but it doesn’t surprise me that there really hasn’t been such a rash of such cases.  Mostly the social media crime stories that you see are instances of Facebook users having their homes burglarized after announcing to 300 of their “friends” that they will be out of town on vacation.

Maybe its the former prosecutor in me, but I really anticipate that the metadata of photographs will be used much more by law enforcement.  For example, take your average Facebook page of someone in their late teens.  How many photographs would you see of the 19 or 20-year-old with alcohol?  Until now, the police could never prove “when” or “where” a photograph was taken, and these are essential jurisdictional elements that are a necessary to bring charges.  But aren’t these two questions conclusively answered by a photograph’s metadata as depicted above?  Before I set any teenage readers into a panic, I should mention that I put this theory to a test.

Can the police determine the location and date of photographs posted online?

I downloaded a few such photographs from Facebook, and attempted to analyze the metadata for location and date.  However, I wasn’t able to recover such information.  At first, I assumed that the photographs were taken by older digital cameras with no geotag capabilities.  However, no such metadata was even recoverable from Facebook “mobile upload” pictures that were clearly taken with iPhones. Even when I uploaded geotagged pictures that I had taken myself, I still could not recover date and location information.  I then emailed Facebook, and they informed me that such metadata was automatically “stripped” from all photographs once they appear on Facebook.  I then asked Facebook if that data would be recoverable from them by law enforcement subpoena.  I have not heard back yet.  I never tested this out with Myspace.  It could be that they strip such metadata too.  But if Facebook protects a user’s “geo-location”, how come Twitter and Craigslist do no also do so?

What do you think?  Will those seeking to commit crimes use such technologies in the future?  In what ways could such technology be abused?

For past blog posts about technology and the law see here, here, here, here, here, and finally here.