It is quite common to find a smart phones which comes fitted with camera and GPS. These cell phones when used to take photographs also stores the location information. The coordinates may not be stamped on the photograph making it visible to all, but they are stored in attribute data with the photo. With sharing of photo quite common, one runs the riks of stangers stripping these information to find out the place where these photographs were taken. There are free tools available which will interpret this information and show on show on Google where this photograph was taken.
Care must be taken to turn off the GPS in the settings of the cell phone, if the location data is not intended to be shared.