Mass. Gen. Laws ch. 164 § 67
No town having within its limits the main gas works or the central electric station, or the major portion of the wires, poles, conduits or pipes used in connection with any such works or plant, shall, except for a violation of the terms or conditions upon which the same were granted or for a violation of law respecting the exercise thereof, revoke any rights granted to any person or corporation engaged in manufacturing or distributing gas or electricity for sale after the introduction of the first vote authorizing the establishment of a gas or electric plant in a city council under section thirty-five or after the calling of a town meeting under a warrant including an article on the passage of such vote, until the proceedings so begun have been finally determined by granting or denying authority to establish such plant. After the ratification of the votes required by section thirty-five and the passage of both votes required by section thirty-six, no town, except as hereinbefore provided, shall revoke any rights, locations or licenses granted to any such person.
Mass. Gen. Laws ch. 164, § 67