A picture's worth a thousand words -- especially for cyberstalkers.
Social networking and smartphones go hand in hand for the web savvy. But few people realize they may be giving away more than they plan to when they post even the most innocuous photos from their Blackberry phones or Apple iPhones.
Most smartphones encode a GPS stamp called a geotag into digital photos they capture, a tag that reveals the exact location a photo was taken by embedding longitude and latitude coordinates. Share that picture on Twitter or Facebook and anyone can instantly discern where you are, warned Ben Jackson, a security analyst and co-founder of the website ICanStalkU.com.
"We take that data, look at the publicly available photos and then map it to an address -- so we can then tell a person was at a certain location when they posted that photo," Jackson told FoxNews.com.
ICanStalkU.com aims to monitor social-network users on Twitter and let them know when they're giving away their exact locations, and it covers people all over the country and around the world. In just over three months ICanStalkU.com has managed to track 50,000 different photos using geotags.
The information can be very helpful when users are trying to sort through old vacation photos, but it also offers criminals an even faster way to hunt for victims online.
"Unfortunately, when people are instantly publishing these photos online it can then provide breadcrumbs to where they were and where they might hang out," Jackson said, adding that tracking someone via geotags is quite simple. "It's easy enough that I can probably teach a grade schooler to do it."
We decided to put Jackson's tracking skills to the test. Heading to a random side street in New Bedford, Mass., I took a quick snapshot and posted the photo online, linking it to my Twitter page. Within 15 minutes Jackson was driving down the street to say hello.
"We start analyzing for patterns. We can start telling where your house is, where you may work, what your favorite haunts may be, a coffee shop, restaurant, a place that you like to go to like a club of some sort," Jackson pointed out. "We can then piece those together and say, 'hey, look at that. Every Friday night they like to go to this bar over on Main Street.'"
People with more nefarious intentions can use that and other data to swipe identities, stalk victims and scout locations. Last Fall, three men were nabbed on burglary charges in Nashua, N.H., after police say they used information gleaned online to help swipe more than $100,000 worth of stolen goods.
Nashua Police Lieutenant Jeffrey Bukunt said he expects that the number of criminals using the web to commit crimes will increase.
"It's something they can do from the comfort of their own home. They no longer have to go out on the street to necessarily case a residence to commit a burglary," Bukunt told FoxNews.com.
Luckily, this functionality is easy to disable on most phones if you don't want it to remain active: The ICanStalkU.com website has details on how to disable geotagging.
Molly Line joined Fox News Channel as a Boston-based correspondent in January 2006.