What if you have a so called "x-ray" camera? Its been shown that certain wavelengths really don't care about clothing and that cameras can pick up these wavelengths so would the person that owns the camera be looking at jail time if he takes a picture of a busy street with it? Because I could see the artistic merit of such a photo, showing how many shapes and sizes and colors we humans come in on just one little bit of street for example, how we are all very different but also the same.
But at the end of the day these kinds of laws always make me nervous as they WILL be abused, they WILL be stretched beyond all reason, its simply a matter of how long it takes. For an example look at the CP laws which were originally to protect kids from predators but thanks to being stretched beyond all recognition you can drag a stick figure and write "nekkid kid getting screwed' and depending on the state you could be looking at just as much jailtime as an actual photo. That is fucked up and I can see these "upskirt" or revenge porn laws also being twisted.