Apparently, this foot tapping in the bathroom thing is nothing new. According to a Washington Post article it's been going on since at least the 1960s. I wonder at what point it became enough of a problem that the police started setting up sting operations to catch these characters? Maybe it was to haze the new officers of the department. Can you imagine hanging out in a bathroom stall all day, just waiting for someone to tap their foot? Excuse the pun, but what a shitty assignment.
For any restroom-sex aficionados out there I apologize, but I just don't understand the excitement in this. I go into a bathroom stall for one reason... and you probably don't want to be anywhere around when I do.