The Government Accountability Office once again slammed the Transportation Security Agency and their use of “behavioral indicators” when screening passengers at airport security checkpoints, citing a lack of evidence to support the notion that the screening method “can be used to identify persons who may pose a risk to aviation security.”

It’s the second time in about four years the government watchdog has been critical of the TSA’s use of behavioral indicators as a screening tool, which uses nonverbal cues such as “assessing the way an individual swallows or the degree to which an individual’s eyes are open,” when trying to determine if an air traveler has “mal-intent.”