Every photo your phone takes carries a hidden second layer: EXIF metadata. Some of it is harmless. Some of it is your exact GPS location at the moment you pressed the shutter.
What is actually in there
Camera model, lens, exposure, the date and time, and — on most phones — latitude and longitude. Post an unedited photo of your home and you may be publishing your address with it.
Strip it on the way out
The safest habit is to remove location data as part of your export, not as a separate step you will forget. SqueezeImages strips EXIF location automatically while it compresses, so a lighter file is also a more private one.