I've screwed this one up before, but it's important for people to get that because things on the internet are largely "public", it doesn't mean that they should necessarily be broadcast on the evening news. That you can see into someone's window when you're walking by doesn't mean you should take pictures and put them on the internets.
There will never be any clear rules, and some people might be "public figures" in some spheres but not others, but those of us with spotlights shouldn't always shine them.
