Massachusetts Rules of Professional Conduct Rule 4.4: Respect for Rights of Third Persons
In representing a client, a lawyer shall not use means that have no substantial purpose other than to embarrass, delay, or burden a third person, or use methods of obtaining evidence that violate the legal rights of such a person.
Adopted June 9, 1997, effective January 1, 1998.
 Responsibility to a client requires a lawyer to subordinate the interests of others to those of the client, but that responsibility does not imply that a lawyer may disregard the rights of third persons. It is impractical to catalogue all such rights, but they include legal restrictions on methods of obtaining evidence from third persons.
Corresponding ABA Model Rule. Identical to Model Rule 4.4.
Corresponding Former Massachusetts Rule. DR 7-106 (C)(2); see also DR 1-102, 7-102(A).