In this subchapter, "picketing" includes the stationing of a person for an organization to:
(1) induce anyone not to enter the premises being picketed;
(2) observe the premises being picketed to ascertain who enters or patronizes the premises; or
(3) follow employees or patrons of the premises being picketed to or from those premises to observe them or to attempt to dissuade them from entering or patronizing the premises.