Should we talk to faculty during their office hours?

I had an interesting conversation with a friend who worked for many years as an academic librarian and now teaches Information Technology at RIT. She is unique in that she has both the librarian point of view and the faculty point of view. She thinks that librarians should come by and talk to her during her posted office hours. That's when she goes and talks to colleagues. It makes perfect sense to her. On the other hand, one of my librarians, thinks it's a terrible idea and totally violates the faculty - student privilege. Hmmmm. I suspect my first friend probably has a useful insight that we should pay attention to.