Take this with a light heart.
Ok, so we've all been there. You answer a question with a perfect answer, but then the question goes dark, falling into the stackoverflow abyss. The OP never comes back and bothers to say, "hey it worked", or "no, that's not what I meant". In fact he never returned to the question, even though he was on the site 10 minutes ago.
So I'm thinking, maybe an overlay gets posted on their avatar with the word tactless, in bright red. I mean, who in a corporate setting goes up to the smart guy and asks a 10 paragraph long question, waits for the guy to finish his answer, then says, "huh? were you talking to me?" Then walks away without ever broaching the subject again. That's tactless.
Let rep 1 guys do it sure, no way to stop it, but not a guy with 600 rep and 86% accept rate that decided he was going to get lazy about 10 questions ago.
All in fun.