In our current culture, creating photos of naked children - even if they are your own - can make you a child pornographer, at least in the eyes of the fanatical religious right. But then, many other people have a somewhat weird understanding of the human body anyway, too. The female body in a very unnatural form - “upgraded” with implants, heavily airbrushed and minus the nipples - is constantly being shoved into your face, whether you like it or not. This all results in a very charged atmosphere for photographers like Sally Mann, who spent a lot of time on taking photos of her own children. Her photos are amazingly honest and in-your-face, and maybe that’s what makes them so uncomfortable for some people to look at.
Lately, she has been working on collodion wet-plate glass photography, see some of her newer work here and here. In addition, you can find extra information and many more links here and here.