Canon 34

CONFIDENCES OF A CLIENT. The duty to preserve his client's confidence outlasts the members's employment and extends as well to his employees; and neither of them should accept employment which involves the disclosure or use of these confidences, either for the private advantage of the member or his employees or to the disadvantage of the client, without his knowledge and consent, and even though there are other available sources of such information. A member shall not continue employment when he discovers that this obligation prevents the performance of his full duty to his former or to his new client.

If a member is falsely accused by his client, he is not precluded from disclosing the truth in respect to his false accusation. The announced intention of a client to commit a crime is not included within the confidences which he is bound to respect. He may properly make such disclosures as to prevent the act or protect those against whom it is threatened.