You have asked our opinion with respect to the following situations.
Your first inquiry is whether you may write a letter attesting to the character of a defendant in connection with the sentencing phase of a matter in which the defendant has pleaded guilty in federal court. Canon 2(B), as you note, states that a judge "should not testify voluntarily as a character witness." We believe that writing a letter such as you describe falls within the letter and the policy of the prohibition contained in Canon 2(B). If there is a formal hearing and you are subpoenaed to testify, then, in our view, you may testify without violating the prohibition.
Your second inquiry relates to your ability to serve on boards of directors of non-profit organizations concerned with "Third World issues," to be a member of an organization that deals with such issues, and to sign letters addressing human rights violations. Your inquiry is quite general and does not present specific factual situations for our comments and our response must therefore be general as well. Canon 4 provides that a judge "may speak, write, lecture, teach, and participate in other activities concerning the law, the legal system, and the administration of justice" provided that "in so doing he does not cast doubt on his capacity to decide impartially any issue that may come before him." Likewise, Canon 5(B) states that a judge may participate in civic activities "that do not reflect adversely upon his impartiality or interfere with the performance of his judicial duties." Canon 5(B) specifically permits service as a director of a civic organization so long as it is not conducted for the economic or political advantage of its members. The permission granted by Canon 5(B) is subject to certain other limitations. One is that the judge should not serve if the organization is likely to "be engaged in proceedings that would ordinarily come before him or will be regularly engaged in adversary proceedings in any court." A second is that a judge should not solicit funds on behalf of the organization, allow the prestige of his office to be used for that purpose, or be a speaker or guest of honor at the organization's fund raising events. Our Opinions 90-2, 91-2, 95-1, 95-4, and 95-8, and the Supreme Judicial Court's opinion in Matter of Bonin, 375 Mass. 680 (1978), apply the general principles outlined above to specific factual situations. The last two citations especially indicate that although judges have considerable freedom to engage in activities like those you describe, there are limits. Thus our advice is that you may do all the things described in paragraphs "a" through "d" of your letter unless the specific situations involve any of the limitations set out in the Canons and other materials cited above.