The opinion of the court was delivered by This was an action to enjoin the defendants from continuing their ambulatory picketing at plaintiff's customers' locations while plaintiff's trucks were delivering ready-mixed concrete. The defendants, Truck Drivers & Helpers Union Local No. 696, commenced following plaintiff's ready-mixed trucks to customer locations in July of 1962, and while patrolling back and forth in front of these locations displayed to the public and to plaintiff's customers a sign publicizing that plaintiff refused to negotiate or bargain with the union.