See Dombrowski v. Pfister, 380 U.S. 479, 486, 85 S.Ct. 1116, 14 L.Ed.2d 22 (1965) (recognizing the "sensitive nature of constitutionally protected expression, in permitting a pre-enforcement action involving the First Amendment); see also Bland v. Fessler, 88 F.3d 729, 736-37 (9th Cir.1996) (That one should not have to risk prosecution to challenge a statute is especially true in First Amendment