The attorney-client privilege defined by Evidence Code section 954 authorizes a client to refuse to disclose, and to prevent others from disclosing, information communicated in confidence to the attorney and legal advice received in return. The objective of the privilege is to enhance the value which society places upon legal representation by assuring the client the opportunity for full disclosure to the attorney unfettered by fear that others will be informed. While the privilege belongs only to the client, the attorney is professionally obligated to claim it on his client's behalf whenever the opportunity arises unless he has been instructed otherwise by the client.
Most states have a similar doctrine, whether by statute or otherwise.