"Defensive upvoting," you might call it. I've certainly done it. I've also seen many of my own comments go up and down quite a lot as the upvoters & downvoters

"Defensive upvoting," you might call it. I've certainly done it. I've also seen many of my own comments go up and down quite a lot as the upvoters & downvoters battle it out. (Eventually they tend to settle on a solid "meh.")