Add me to the over group.
It depends. Public washrooms, absolutely. But I believe in one's right to be as wrong as they want in their own home, so I won't change it in a private residence...unless it's my family or a close friend.
Fun fact: I have come to the realization that my parents embrace anarchy and chaos. I've often found myself changing their TP to over and thought that they just weren't paying attention to how they put the roll on. When I was there last week I changed it to over. I went to the bathroom again a few hours later and that same roll had been changed back to under. That's when I knew it was deliberate. My own parents!