15 U.S.C. § 36: Recovery of damages, etc., for antitrust violations on claim against person based on official action directed by local government, or official or employee thereof acting in an official capacity

(a) Prohibition in generalNo damages, interest on damages, costs or attorney’s fees may be recovered under section 4, 4A, or 4C of the Clayton Act (15 U.S.C. 15, 15a, or 15c) in any claim against a person based on any official action directed by a local government, or official or employee thereof acting in an official capacity. (b) Nonapplication of prohibition for cases commenced before effective date of provisionsSubsection (a) shall not apply with respect to cases commenced before the effective date of this Act.