HONOLULU (HawaiiNewsNow) - Trevor Ridinger's smart phone doubles as his camera. It's the University of Hawaii student's window to the world.
"I have an iPhone 3GS. I take pictures maybe three of four times a week. Usually, I upload them to Facebook," he said.
Encrypted onto his photos, invisible on the surface, are data bits called geotags.
"These days cell phones and even cameras have GPS built into it. So whenever a photo is taken it's also including the longitude and latitude location there on the map," said James Kerr, who owns computer company SuperGeeks.
The embedded information records where a photo's taken.
"Say someone is stalking you and you take a picture at your home and you post it to Facebook, Twitter or someplace. With the right tools someone could determine exactly where that photo was taken. And by exactly, I mean within 150 to 200 feet," Kerr said.
"I think that's kinda scary. I don't think people should know exactly where you're at all times," UH student Kara Schumacher said.
Geotagging works hand in hand with GPS.
If you're concerned your photos may be saying too much, your iPhone geotag program can be disabled in the Setting's application and turned back on when you want it.
Another safeguard is being careful where you post your pictures.
"When I upload my pictures on Facebook, only my friends can see them so I'm not worried about my friends stalking me," Ridinger said.
Geotagging can be a helpful tool.
But in the wrong hands the information hidden to the naked eye could be very revealing.