I've never been very good at using the phrase, "That's none of your businesss," when someone asks me a question I don't want to answer. I usually wind up answering the question, at least in part, and kicking myself for doing so without at least asking the questioner why he or she wants to know.

But something I realized just today is that dealing with someone's questions by e-mail provides a perfectly wonderful way of dealing with these situations---you just fail to answer the offending question, while being careful to address other things the writer brought up.

If the question gets asked a second time, ignore it again. And so on.

I suppose I'm the last person on earth to figure that one out!