EXIF tags in images can have your camera and GPS info. You can clear EXIF tags before sharing files. Most social networks will remove EXIF tags from pictures

EXIF tags in images can have your camera and GPS info. You can clear EXIF tags before sharing files. Most social networks will remove EXIF tags from pictures before serving them to other people. Except silly social networks used by insurrectionists. But even without the EXIF tags there's plenty of info that can be extracted from a picture. Face biometrics is one of them.