I am interested in several things:- is it possible?- how to do it?- is there a way for a sysadmin to configure  the machine so that it will beep or send  an e-mail to the user so that he is aware that someone  is watching his screen.I am interested in Linux primarily.If there are general guidelines for BSDs, I am interested in them too.I think doing this is illegal in many countries.I suspect one of my bosses was doing it in the past.As a user, I'd like to know how to configure the machine to defend against this.As a sysadmin, I feel doing this is completely unethical.
Is it possible for a sysadmin to eavesdrop a user's screen/graphics?
x11;security;privacy