Most modern cameras and smart phones store extra information in the pictures you take. They can save your camera make, model, how the picture was taken, the date and time, and if your camera or smartphone has a GPS module, the coordinates where it was taken. You may be sharing your home address when you upload your barbecue pictures. Some models may even store a small copy of the original image inside the file. If your editing software does not remove this small image, even if you modify it, anyone could see the original picture stored inside.
If you like sharing your pictures, and privacy is a concern for you, "Photo Privacy" can help you by removing all that information from your pictures. It creates a private copy of your pictures, which you can use to upload to your favorite social network or image hosting service, being sure that no private data is stored in the image.