You make a good point, but in truth, doesn't quite work out as well as you intend it. You see, I have every right to ask a user why they want to do something. Afterall, if I choose to help someone, it's my choice whether or not I should help them. If they are doing something I don't agree with, I don't have to help them.The techonology is the only issue. PHP doesnt have a license that says "thou shalt not X", so why should these forums?
I agree that I think it's wrong that any moderator should close a thread because they don't agree with what the poster is trying to do (with very few exceptions, for example, someone needing help with protecting his child porn site from authorities is not going to get help from me, and I will quickly close the thread), but neither do I think it's a posters responsibility to help everyone and anyone.
Nor do I see it a problem to warn someone about the possible consequences of doing something illegal. Handing someone the code without a word of warning is not professional. At the very least, it might provide someone with some additional information they didn't have before.
Anyways, the point is that asking the question is not a problem, but banning a conversation because someone doesn't agree with it's uses is a bit extreme, and generally frowned upon.
We can take a step back and pat ourselves on the back, and say "Sure, we just built the bomb, but he is the one who set it off." Yeah, sure, then we get into a bigger dilemma, and a bigger debate.