I'm unable to find it. The only written instance that is easily searchable is from a newspaper article from late 1800s that just mention its use. The account I seem to remember was a historical account of person(s) in the stock or pillory, who were not so hated by the public, and them being pestered in this manner, rather than the common harmful ways. It was not as a planned ordered thing. Rather it was just what some choose to do to them. In any case, offenders were held in these to leave them to the mercy of the mob, who often did very cruel things to them, so its easy to assume they also did this.