I'm with cartera and christcorp (edit: and now Susan). I'd find some non-stalker way of telling him what I found and suggest strongly to him that he protect himself. My relationship with my D would allow me to just say it , but then again she thinks I'm a lunatic and that always helps in times like these. Prior insanity sets up this conversation quite nicely - "Hey, kid. I was googling your name to see what the world was saying about you and I found this personal crap. You better watch yourself. There are wierdos in your woods. Still no rumors about you from the Nobel folks. Oh well. Maybe next time."
But let's remember it was me who coined the phrase during her sports/high school career "If it ain't vicarious, it ain't really living."
Some folks might object.