Mass. Gen. Laws ch. 123B § 9
A person with an intellectual disability in the care of the department shall be provided with stationery and postage in reasonable amounts and shall have free and unrestricted mailing privileges.
A person with an intellectual disability shall have the right to be visited at all reasonable times by anyone unless he is ill or incapacitated and the superintendent determines that such a visit would be unreasonable. A statement of the reasons for any such denial of visiting rights shall be entered in the treatment record of said person.
In addition to the rights specified above and any other rights guaranteed by law, a person with an intellectual disability in the care of the department shall have the following legal and civil rights: to wear his own clothes, to keep and use his own personal possessions including toilet articles, to keep and be allowed to spend a reasonable sum of his own money for canteen expenses and small purchases, to have access to individual storage space for his private use, reasonable access to telephones to make and receive confidential calls, to refuse shock treatment, to refuse lobotomy, and any other rights specified in the regulations of the department; provided, however, that any of these rights may be denied for good cause by the superintendent or his designee and a statement of the reasons for any such denial entered in the treatment record of such person.
Mass. Gen. Laws ch. 123B, § 9