Several mishnayot - beginning with nullifying an idol (on the bottom of the previous daf). Note that a non-Jew nullifies the idol, not a Jew, and only a non-Jew who owns at least part of the idol. Acting in excruciatingly, disrespectful ways before the idol will not nullify it. Also, the idols that were in the land when Joshua conquered it, and the tolerance for idolatrous practice that they Jews were willing to entertain during the sin of the Golden Calf. Also, an object of idolatry that was set aside during a time when the non-Jews would have had ample time to go get the master. (as compared to a peace time, when there's no way to know why the idol was shunted aside).