There has probably never been a period in time when so many people take photos and exchange them, post them, or develop them, as we see in today's present world. The ease of taking pictures, the fact that you can take photos with your phone camera, or with your digital camera, and the reality that your pictures do not need to go through the step of being actually developed by a photo-print shop, means that people are taking more photos than ever. The bottom line is once you obtain your phone camera, or dedicated digital camera, with the exception of storage space, you can snap as many photos as you desire, without having to worry about absorbing any additional monetary cost.
While the above is all well and good, there are general privacy concerns that most people are oblivious of when it comes to the photos and the data that is stored. I suspect that most people, would take it as a given that the camera that records the shot, also records the date and time, along with probably recording the camera type and speed, as well as the aperture size. There may be some people that definitely know that their particular camera will also record their GPS location, and thereby love their camera for that feature, because it allows them to shoot a lot of pictures on, for instance, a traveling excursion, without having to wonder exactly where they took that picture later, when they try to piece it all back together. Finally, for more professional type camera users, they understand the importance of metadata in protecting their copyrighted images and hence would be strong supporters of any metadata associated with their photos.
So what exactly is metadata? When it comes to photography, metadata is all the data that is stored, and usually hidden behind the picture, that is invisible to the picture while containing the properties of the picture and ultimately storing all the pertinent data of the photo, which includes but isn't limited to: date, time, camera used and possibly its S/N, dimensions, pixel resolution, exposure time, focal length, GPS locale, lens used, and so on. The details behind each photo that you have taken then are both highly comprehensive and quite specific, and consequently should be something that you may want to consider seriously before sending or posting photos, as the sites that you post or send your pictures through, may or may not remove some or all of your metadata behind your photographs.
As with most anything, metadata can be your friend and aid, as well as your enemy and downfall. For those that take photos as well as for the people that are captured within the photos, the photographer must take responsibility for protecting the privacy of the people that he has captured within his lens. Most pictures today that are posted, tell a story, and not just the story contained in the photograph in front of you, but the story that is contained hidden behind the picture. That data can be used by law enforcement, stalkers, creeps, and weirdo's in such a way that you may well be faced with a situation which was wholly unintended yet comes with disastrous consequences to yours or to other's personal s well-being.