Cal. Penal Code § 311.7

Every person who, knowingly, as a condition to a sale, allocation, consignment, or delivery for resale of any paper, magazine, book, periodical, publication or other merchandise, requires that the purchaser or consignee receive any obscene matter or who denies or threatens to deny a franchise, revokes or threatens to revoke, or imposes any penalty, financial or otherwise, by reason of the failure of any person to accept obscene matter, or by reason of the return of such obscene matter, is guilty of a misdemeanor.