Conversations in bathroom stalls are unacceptable. You should not talk to your stall neighbor while you both know what's happening on either side of those thin, too short, metal walls. Period. Nor does the stall double as a phone booth. It is not a private setting and it's just plain weird for all involved if you talk while you're micturating.
I walked into the restroom at work today, and as I closed the stall door behind me, I heard a voice from the other side say, "Well, hiiiiiii there princess!"
That creepy greeting was not for me, was it?
Nope. The person using the stall next to me had just placed a phone call, and felt comfortable saying that. The way she said it would have been creepy anywhere. Especially so on the toilet.