Many of us are careful about what we post on Facebook, Twitter, and other sites. We avoid giving exact locations on status updates and we don't use FourSquare or Loopt (or similar apps) to tell our online friends where we are.
Still, you may not realize you're over-sharing through photos taken on your smart phone.
It's called geotagging.
Most smart phones like Droids, iPhones, and Blackberrys are equipped with GPS technology. When you send out a photo, a lot of information (including what time the photo was taken and where it was taken) is sent out with it.
"What your camera will do is tag it for your location. It goes up and says ok, I know that you're standing at this position and I'm going to put that information into your picture," said Vicki Sauter, professor of Management Information Systems at the University of Missouri - St. Louis.
Someone with pretty basic software could easily read the data hidden in the photo to find the latitude and longitude to figure out where the photo was taken.
This could be dangerous for victims of domestic violence. Meg Schnabel, the executive director of Redevelopment Opportunities for Women, always advises victims of domestic violence to avoid social networking sites. Still, many may assume that photos are harmless.
"Women who are experiencing violence and abuse from a partner and who are vunerable to abuse and violence from that partner need to know that this is just another way that they can be tracked," said Schnabel.
You can disable the function on your phone if you choose to.
PC World offered instructions in this article: www.pcworld.com/article/205296/what_your_digital_photos_reveal_about_you.html
Another website publishes information it collects from people who Tweet geotagged photos: icanstalku.com/
The ICanStalkU website is simliar to another you may have heard of. PleaseRobMe.com used information found on social networking sites to high-light just how much personal information is posted on-line.
The site also offers tips so you can check your settings: icanstalku.com/how.php
If you still have trouble, contact your cell phone provider and ask about disabling geotagging on your camera phone.
Keep in mind, even if you check your settings and disable geotagging, your friends may not. Someone could easily take a photo of a meal you cook at your house and post it online. Even if they're not giving out your address, someone could read the data in the photo to find geographic information.
Inevitably, someone will say that this story teaches someone with ill-intentions how to use this function. However, this story also shows everyone else how to protect themselves.