Posting picture of your naked children?

While on Facebook I came across someone I know posting a picture of her daughter at the family lake house. Her daughter was standing on the dock completely nude. Her daughter is 8. Someone else I know was pretty upset over this and reported the picture to Facebook, but the response back from Facebook was that it didn’t violate any of their community guidelines. The mother has actually married into my family recently, so I know her pretty well and her daughter is almost always nude. My fiancé and I have stopped visiting because now that she’s getting older and still won’t put clothes on it’s becoming uncomfortable to be around them. I don’t think we should sexualize children, but unfortunately not everyone has good intentions, and when you have hundreds of people on your Facebook, many you’ve never even met, you don’t know what’s being done with that picture of your child, or where it’s going to wind up. I’m curious to get opinions from others though.