I'm with yb, Rouxb, and oilgun on this.
Doctors and lawyers don't get followed around by people looking for medical and legal advice in their private time. They make a lot of money. Some of them are even famous.
I don't think actors owe us anything but the best job they can do on a movie or in a play at any given time. It's one thing to do the publicity circuit for a movie to promote it, and to do photo shoots for magazines to promote yourself and/or your projects. It's another to be stalked by vultures looking to make a buck off *your* looks and talent with no regard for your dignity. They don't owe anybody that.
I've been in situations where I've seen famous people in private life, and if I were so inclined, I could have gone right up to them and asked for an autograph or whatever. I won't do it. I'll wait outside the stage door at a play, or I'll go to a book signing or Q&A at a film screening - there, they're purposely putting themselves out there for the fans. But I refuse to interrupt a person's meal, or buying Starbucks coffee with his manager, or bicycling with his longtime friend, or watching her husband play a tennis match, to gush all over him or her. It's just rude.