As I don't have the karma to downvote, my approach, which is likely to remain unchanged even if I ever get to the appropriate karma threshold, is to simply ignore. My mindset on this has been (and not saying it needs to be anyone else's) that my parents taught me ignore taunts, bullies, etc. and I simply extended it to this. I don't even want to put in the effort of downvoting to give the impression that I find someone's post or comment worth the effort of doing so.