Pretty simple and not to long Photoshop tutorial, where you will add a random photo of a person onto a rock and then make it look like it's been engraved.
Camera images usually contain additional description about camera settings and scene information of the the picture taken. By using EXIF, you can view this data online.
If you are afraid of being hacked or someone else using your Facebook account you can enable option that will send you an email or text message in case your account has been accessed from a device that you never used before.