Privacy, it's what Americans cherish most. It's the reason we have search warrants, Roe v Wade, and various other ordinances designed to protect one's right to freely dance about it in a Rainbow Brite costume to the funky beats of Abba in the comforts of our own dwellings.
Not that anyone should do that, but most expect privacy in areas outside of their domain. Note one guy at work, who feels it's necessary to attach a long yard of toilet paper to the door hinge inside the bathroom stall to ensure no one peeks in. Yes he's afraid of people looking at him squat on the porcelain chair.
The child in me wants to reach over the stall and grab the makeshift curtain, rip it out, and point my finger and scream "YOU'RE GOING POOP. YOU'RE GOING POOP."
I guess that wouldn't be polite, but dude you're in a public bathroom. Do you really think people are trying to look in at you? I mean they do when I'm in there, but only to check out what an Adonis I am. Everyone wants to take a look at perfection. Oh and I poop gold. True story.
"I urge calm and sensitivity to the fundamental civil liberties of our country." - Larry Craig