Mass. Gen. Laws ch. 112 § 52G
No person filing a complaint, making a report, providing information or otherwise assisting the board for purposes of said board's discharge of its duties and functions pursuant to sections forty-three to fifty-three, inclusive, shall be liable in any cause of action arising out of such filing, reporting or the providing of such information or assistance; provided, however, that the person filing such complaint, making such report or providing such information or assistance does so in good faith. In any action brought against a person filing a complaint, making a report, providing information or otherwise assisting the board, where it is determined to be unsubstantiated, frivolous or in bad faith, the court shall award reasonable counsel fees and costs and if the person defending such action is not represented by counsel, the court shall award an amount equal to the reasonable value of such person's efforts in defending such action. The court shall state the method by which any such award is determined.
Mass. Gen. Laws ch. 112, § 52G