Okay, this is sorta creepy — and if you aren’t aware of this little fact by now, you should be: Unless you’ve adjusted the settings to turn this feature off, every time you snap a photo with your iPhone it embeds data with your exact location in the image file. This data, called a geotag, can be easily read using easily available software by anyone who has access to your images online (btw, contrary to what the folks at NBC say, it’s not new technology; the ability to geotag photos has been around since at least the first iPhone to include GPS, the 3G).
Strip Private Location Info From Your Images [New Mac App]