many cameras add metadata to photos - camera make/model, date etc ... but also often geographic location. This is stored in a part of the image file called "EXIF" metadata. They're easy to remove, but i guess many people either don't know about it or forget. Well, at least you won't be one of the people who don't know about it.
http://thehackernews.com/2016/09/dark-web-drug-weapon.html
http://thehackernews.com/2016/09/dark-web-drug-weapon.html