Cell Phone Etiquette

To the young woman in the public restroom yesterday:

It is not cool to talk on the phone while in the ladies' room. It is really not cool to talk on the phone while you are in a stall, utilizing the facilities. Based on your conversation, I know that you are a student in a creative writing course. I hope this doesn't mean I will run into you on a regular basis - I'm not sure I could keep myself from rolling my eyes or laughing.