Cal. Business and Professions Code § 6090.8

(a) (1) A licensee of the State Bar who knows that another licensee has conspired to engage in or has engaged in any of the following shall inform the State Bar: (A) Seditious conspiracy as prohibited under Section 2384 of Title 18 of the United States Code. (B) Treason as prohibited under Section 37 of the Penal Code or Section 2381 of Title 18 of the United States Code. (C) Rebellion or insurrection as prohibited under Section 2383 of Title 18 of the United States Code. (2) For the purpose of this subdivision, “knows” means actual knowledge of the fact in question. A licensee’s knowledge may be inferred from circumstances. (b) This section does not require disclosure of information otherwise protected by the attorney-client privilege or information gained by a licensee while participating in the Attorney Diversion and Assistance Program. (c) A licensee of the State Bar who makes a complaint to the State Bar pursuant to subdivision (a) with the intent to intimidate, harass, or otherwise deter a fellow licensee from engaging in the lawful practice of law shall be deemed to have committed professional misconduct. (d) The board may amend the Rules of Professional Conduct, and shall propose those amendments to the Supreme Court for approval, to implement this section.