Is it a violation of a ban on providing "expert advice or assistance" in support of a foreign terrorist organization?

At oral argument, the government stated that filing an amicus brief in support of a foreign terrorist organization would violate AEDPA's prohibition against providing "expert advice or assistance." Because the "other specialized knowledge" portion of the ban on providing "expert advice or assistance" continues to cover constitutionally protected advocacy, we hold that it is void for vagueness. See HLP I, 205 F.3d at 1137-38; NAACP v. Button, 371 U.S. 415, 432-33, 83 S.Ct. 328, 9 L.Ed.2d 405 (1963) (noting that vagueness and overbreadth depend on "the danger of tolerating, in the area of First Amendment freedoms, the existence of a penal statute susceptible of sweeping and improper application").