Few principles of law have been as rigorously adhered to as the attorney-client privilege. With narrow exceptions, the privilege bars an attorney from revealing information provided by a client. Indeed, there has been serious debate as to whether a lawyer is allowed to reveal even information received from a client concerning the client’s past or future commission of a crime. Here’s how the Supreme Court of the United States explained the attorney client privilege:

Confidential disclosures by a client to an attorney made in order to obtain legal assistance are privileged. * * * The purpose of the privilege is to encourage clients to make full disclosure to their attorneys. if the client knows that information could more readily be obtained from the attorney following disclosure than from himself in the absence of disclosure, the client would be reluctant to confide in his lawyer and it would be difficult to obtain fully informed legal advice.

Professor Wigmore, a preeminent American authority on the subject, has defined the attorney-client privilege this way:

“Where legal advice of any kind is sought from a professional legal adviser in his capacity as such, the communications relating to that purpose, made in confidence by the client, are at his instance per­manently protected from disclosure by himself or by the legal adviser, (unless] the protection be waived. more