Out of the forum regulars, we know who the heavy smiters are, and who thr people we disagree with often are. As an example, I almost always disagree with 2 forum vets, and I never notice my smite count change when we argue, and I don't smite them either since its irreconcilable opinion differences, no big deal. That means the smites I have noticed were probably someone I've barely spoken to. Again, it happens, no big deal.
Plus, sometimes weird things bother people. Screen names, story ideas, houserules etc sometimed rub people the wrong way for whatever awkward reason. Maybe someone really hates Victor Hugo, and my SN reminds them of the Lit Professor From Hell. Or has a horrible intolerance for bad English, or sexuality in their games, or your avatar pisses them off (I'm looking at you, Mirikon. Still cant tell what thats a pic of :p)