Imagine opening a random website, maybe with an article that looked interesting, only to find that YOUR KIDS' PICTURES are used on the site without your knowledge or permission. What's worse is that the author is claiming that they are HER kids!
That happened to a few women recently when they discovered that their babies' pictures were being used in a sick Instagram "game."
The best way to protect your priceless images is to make it more annoying for someone to use them. You can add a simple watermark to the pictures to help deter thieves from reusing your photos.