It sounds like the root problem is that the commenter didn't show you the respect of actually reading your post. My inclination would be simply not to answer. If a person doesn't read your material, and just puts up some knee-jerk response, a thoughtful discussion is unlikely. On the other, I don't think a single instance merits a mute. People have bad days, after all. Now, if the commenter wanted to become lil's personal nemesis, following you from post to post with obviously malicious intent -- I would actually encourage you to mute him, her, or it. If you feel "victimized" by anybody's random internet potshot (pun intended) the problem is, however, probably as much yours as theirs. I do understand -- I myself am all too sensitive to the sting of criticism -- but I know that expecting the whole world to play nice is ultimately paralyzingly. As human beings, we are stronger than that.