In the courses (Solaris, Perl, Networking) I often do the same. Replying to questions with counter questions. There can be several reasons for counter questions.
- A question arises from a wrong assumption of how things are. By asking questions you can quickly narrow down where the wrong assumption is being made.
- It can give the student a much better understanding of why a question has a certain answer. Understanding is far more valuable than knowing.
- Sometimes a question is phrased so poorly (often by lack of understanding or knowing) that there is no answer, or the answer doesn't help the student. Asking counter questions can be more helpful than saying "Your question doesn't make sense".
Unfortunally, if you apply such techniques on the net, be it on Usenet, web forums like this, and also on IRC, you are quickly labelled as being a bitch. For some reason, it's often expected to just give the answer.