Mass. Gen. Laws ch. 149 § 24
No person shall be punished criminally, or held liable or answerable in any action at law or suit in equity, for persuading or attempting to persuade, by printing or otherwise, any other person to do anything, or to pursue any line of conduct not unlawful or actionable or in violation of any marital or other legal duty, unless such persuasion or attempt to persuade is accompanied by injury or threat of injury to the person, property, business or occupation of the person persuaded or attempted to be persuaded, or by disorder or other unlawful conduct on the part of the person persuading or attempting to persuade, or is a part of an unlawful labor dispute or unlawful secondary boycott, or is a part of an unlawful or actionable conspiracy and not a part of a lawful labor dispute, nor for attending in the course of a lawful labor dispute, at any place where such person or persons may lawfully be, for the purpose of peacefully obtaining or communicating information or of so persuading or attempting to persuade.
Mass. Gen. Laws ch. 149, § 24