Well this was in London. It's a large embassy obviously. They do have separate entrances--we went to the US Citizens one. We were blocked from even entering the security lobby at all--the outermost door to the street was locked and the guard who cracked it open gave us a postcard with the embassy contact information to make an appointment. I called them immediately and explained I was in front of their building and could I make an "appointment" for right then, but they said I had to use the website. Which told me there was a 10-day wait.

As I said, apparently this practice was instituted just last year.