picket line(это редкий вариант перевода, обычно picket line – это линия пикета (линия, образуемая протестующими людьми): A picket line is a horizontal rope along which horses are tied at intervals. The rope can be on the ground, at chest height (above the knees, below the neck) or overhead. The overhead form is usually called a high line.CopperKettle)
