I had never given it much thought, but we should all be aware that digital photos may contain location information that we may not want everyone to see. Camera phones add this information, which is stored along with the photos. Photo organization programs may also add information to the photos.
The information stored with photos is called metadata. Some online sites, including Flickr and Picasa, keep it with the original photo; others, such as Facebook, remove it.
Keep this data in mind the next time the next time you post photos of your priceless artwork, your gold coin collection, or even photos of your kids. After all, you may not want everyone to have this information. CNN recently highlighted this concern with Digital photos can reveal your location, raise privacy fears.
To view metadata I use a free tool, exiftool. This program tells me exactly what information is included with a digital photo. Other programs are also available.