The US Court of Appeals for the Ninth Circuit on Monday upheld an Oregon district court ruling in favor of the government’s decision to include four persons on the No Fly List, which prohibits them from boarding commercial aircraft flying to, from, or within the US or through US airspace.

Plaintiffs argue that the criteria for inclusion on the No Fly List are unconstitutionally vague and that the challenging procedure violates their procedural due process rights.

On appeal, the Ninth Circuit held that a law is unconstitutionally vague when it “fails to give ordinary people fair notice of the conduct it punishes.” In the present case, however, the No Fly List criteria are not impermissibly vague merely because they require a prediction of future criminal conduct, or because they do not delineate what factors are relevant to that determination. The criteria are “reasonably clear,” the Ninth Circuit said, because the alleged specific conducts involves plaintiffs’ association with terrorists, training with militant groups overseas and advocating terrorist violence.

After balancing (1) the plaintiffs’ liberty interests; (2) the risk of an erroneous liberty deprivation; and (3) the government’s interest in national security, the court held that plaintiffs’ procedural due process rights were not violated.

Finally, the court held that district court did not err by rejecting plaintiffs’ substantive due process claims for lack of jurisdiction under 49 USC § 46110 because the review of Transportation Security Administration (TSA) orders is put on the courts of appeals rather than the district court.