Not illegal really, just sketchy and probably unethical (not on my part but on the student's part).
Well, I vote against it.
Bitcoin is going to have a rough enough time as it is, when shock jocks in the media start loudly proclaiming that bitcoin is used for money laundering and for buying illegal drugs, when they say anything at all.
So the last thing we need is appear to approve of any unethical deals. That will hurt every bitcoin user.