United States v. Williams, No. 06-694, 128 S.Ct. 1830 (May 19, 2008) (finding constitutional a statute criminalizing, in certain specified circumstances, the pandering or solicitation of child pornography, rejecting claims the statute was overbroad under the First Amendment and impermissibly vague under the Due Process Clause because the term "simulated sexual intercourse" might include virtual child pornography or sex between youthful-looking adult actors).