Privilege Waived for Email Copied to Unrepresented Third Party

Common interest agreements allow separate parties pursuing a common legal interest to share information protected by the attorney-client privilege without waiving that privilege.

But a common legal interest requires that both parties be represented by counsel at the time of the communication, according to the U.S. District Court for the Southern District of California. A common business or commercial interest is not sufficient to protect otherwise privileged communication from disclosure.