Re: "it’s pretty disappointing to see you share our private messages"
The counter part to that is the publication of a private conversation is a deep betrayal of trust, and the effective termination of a working relationship.
Anyone that that publicises a private communication within an organisation is heading to the exit door from then on.
People that would take such a course of action do not deserve the privilege of working with others and are better suited to sweeping the gutter.
Biting the hand that feeds IT
