Ooo. I had that happen two summers ago. But the eggs hatched. I think I must've looked in there one too many times (dang it, they were cute!!) and the mom amscreed. So I called Raptor Rescue and took them, plant and all, to the rescue lady to nurse them. Moral of that story? Don't look at them.
Off topic, but when I was in college, I left my crank window open one day, and later found a bird's nest in the crook. I couldn't close the window, and then she had babies that would chirp at 5:30 a.m. (not cool after a night out!!). We had a HUGE storm, and the mom left, and the babies (I think) froze to death. So then I had a nest of DEAD birds, and no way to remove them. I called maintenance, but they couldn't come until Monday and I cried every time I looked out the window. Eventually poked a hole in the screen with a wire hanger and knocked the nest down. At least I wasn't responsible for THAT one.