Cal. Civil Code § 1798.90.05

Section 1798.90 does not make it unlawful for a law enforcement entity subject to Section 2000aa of Title 42 of the United States Code to obtain a search warrant for the personal information of a user pursuant to otherwise applicable law in connection with the investigation or prosecution of a criminal offense when probable cause exists to believe that the person possessing the personal information has committed, or is committing, a criminal offense involving the production, possession, receipt, mailing, sale, distribution, shipment, or transportation of child pornography, the sexual exploitation of children, or the sale or purchase of children prohibited by Sections 2251, 2251A, 2252, and 2252A of Title 18 of the United States Code. Nothing in Section 1798.90 shall prevent a provider from complying with a proper search warrant issued by a duly authorized court in connection with the investigation or prosecution of any of those offenses.