You should know that an image file contains more data than just the color of its pixels. Hidden within an image file is information known as metadata. Metadata can contain a wide variety of information, most of which is mundane, such as image size and camera model. However, some metadata can pose real concerns for users who want to protect their privacy, while sharing files over the Internet. For instance, images usually store the time and date that they were taken. Such information is easily visible in photo viewing software and Internet browsers.
A more troubling development in metadata is geotagging. Geotagging means storing the precise location where a picture was taken, usually by using GPS, and is a feature which comes pre-enabled in some cameras and many smartphones, including all new Android, iPhone, and BlackBerry phones. And although geotag data isn’t accessible through most commonly-used software, informed computer users, potentially including stalkers and burglars, can still access it. For example, some photography software, designed to read camera settings from images, can also read and display images’ geotag coordinates. And because metadata is preserved when images are uploaded to social media and photo sharing websites, this information can easily be extracted to discretely track an Internet user’s whereabouts and habits.
Geotagging, though occasionally useful to law enforcement, is increasingly being used to malicious ends. Consequently, smartphone users who wish to preserve their privacy should make sure to disable their phones’ geotag feature before they take pictures that they wish to publicize. Removing geotag data in existing images is also possible, most easily by using the “Details” tab while viewing image properties in Windows, or by using third-party metadata removal tools.