Actually, employers can be very helpful. As an employee, I have been involved in several situations similar to this and we have turned away phone calls, had security or someone else walk someone to their car after work etc.
I think it is important people do know so that they are not fooled by a seemingly innocent question from a stranger or "friend of" that winds up being a way to find someone and hurt them.
A coworker was once kidnapped from the parking lot one place I worked. Very scary----she got away and the man was caught...
The state here changed their training after losing someone to a stalker---before that they thought it wasn't their business, the event changed their minds and they now specifically tell people about the event (years ago now) and what they can do if you are in a difficult personal situation such as this.