One of our custom off topic close reasons is the following:
Questions asking us to break the security of a specific system for you are off-topic unless they demonstrate an understanding of the concepts involved and clearly identify a specific problem.
However, isn't the purpose of this site to gain understanding?
The basic purpose of this close reason is obvious, it's to get rid of "TEACH ME TO HACK FACEBOOK!!!111"-type posts1. However, black hat posts seem to be allowed (see Clarify our stance on black hat questions and the linked meta posts)
Does anyone have any better wordings for this? (Or is it OK to keep the current one) It should capture the blackhat policy succinctly.
1. These close reasons were put in place by the community team after looking at a list of recently closed questions, so it ought to be common enough a close reason.