Essays for sale: cheating classmates

(This is a true story)
Two psychology students asked to see the Head of their Department (me) to discuss “an important matter". 
“One of our classmates hires ghost writers and receives better marks than we do,” stated the students in angst. 
“That is dishonest and unacceptable.  Would you care to tell me who is it?” asked the Head.
The students looked at each other and then replied with hesitation, “We cannot do that.”
“So… what do you want me to do?” retorted the Head.
“Find out who it is, and penalize him.”
“How will I do that, if you won’t tell me who it is?”
“Surely you must have a way.”
“I am afraid if you don’t tell me, I won’t be able to penalize the plagiarist.  He will get better marks than you, graduate and eventually be hired instead of you!  Care to tell me now?”
“… We cannot.  It is unethical.  You see, we are classmates, he is our friend.”
“In that case, perhaps you can extend a warning and explain to him that, although you will not give him in this time, you will have to, if he continues.”
“It is not that easy.”
“It appears to me that you are a little perplexed.  You have come to consider the ethical behaviour unethical.  If you passively accept the offence, you also have to accept the consequences and with your inaction you contribute your share to the unfairness and the injustice in academia and in the society.  Good luck with your choices!"

AUTHOR's note: There will always be some bad apples. The real issue is whether hard working students/citizens will act and help reduce unethical behaviours/corruption..

---