Keyloggers of course belong to the category of hacking tools and though they have perfectly legitimate uses, they can also be, and often are, misused for spying other people, notably obtaining their passwords, e.g. to bank accounts.

In view of their above considerable potential for misuse, which cannot be controlled by the board, is discussion and advice on keyloggers allowed on this strictly lawful board?

Its a pretty grey area, but so are other things that get discussed here. The thread you are talking about, as is, had a plausible explanation for needing it.

Personally, I think the dude should handle the situation entirely differently, but we aren't here to tell people how to live their lives. He asked a question and had an explanation, he got an answer, and the thread is pretty much done.

In the future we may get someone bumping the thread and looking for a darker aspect of how to use one, and at that point it will be closed/edited/deleted as needed. But I don't feel the need to do that at this point.