Cal. Probate Code § 879.2

Unless otherwise ordered by the court, directed by the principal, or provided by a power of attorney, a custodian shall disclose to an agent with specific authority over digital assets or general authority to act on behalf of a principal a catalogue of electronic communications sent or received by the principal and digital assets, other than the content of electronic communications, of the principal if the agent gives the custodian all of the following: (a) A written request for disclosure in physical or electronic form. (b) An original or copy of the power of attorney that gives the agent specific authority over digital assets or general authority to act on behalf of the principal. (c) A certification by the agent, under penalty of perjury, that the power of attorney is in effect. (d) If requested by the custodian, either of the following: (1) A number, username, address, or other unique subscriber or account identifier assigned by the custodian to identify the principal’s account. (2) Evidence linking the account to the principal.