It's a matter of ethics!

"Oh my God!" exclaimed my friend, "You're actually speechless. I've never, ever known you to be lost for words before."
It's true, I was lost for words, speechless, dumbstruck.  Processing what had just been shared had quite literally taken my breath away.  I was finding it so hard to comprehend.  To understand and rationalise, What! How! Why???? this was butting up against all the rules in head.  And, boy, was I having an emotional response to this too? Oh yes.

So what had been shared...

My friend had had lunch with her friend, who had her relation staying for a while.  They were having counselling whilst visiting. (With me so far?) "the counsellor said there is just one word to describe your relation, vile."

One word. Confidentiality 
It's worth repeating, CONFIDENTIALITY.  Confidentiality is a key component of the trust.  Confidentiality is essential in the relationship between the client and the therapist.  This is broken only in exceptional circumstances (fraud, terrorism and safeguarding) to the appropriate authorities.  
I have a code of ethics that has strict guidelines about confidentiality for current and past clients (living or dead) and also for potential clients.  There is no way that I will tell you how 'they' are doing...even if you're paying, my contract is with the person/people in the room at that time.  That is between me and the client. SIMPLES!
The cases I take to supervision, the client's identity remains confidential.  Still SIMPLES, it's that easy!