U.S. Transportation Security Administration efforts costing $200 million a year to spot potential terrorists by observing behavior are ineffective and lawmakers should limit funding, the Government Accountability Office said.

TSA’s techniques couldn’t be validated in a review of 400 studies of behavior detection spanning 60 years, the GAO said. A review of the program’s referrals and resulting arrests — none of them related to terrorism — showed it’s barely more effective than chance, the GAO said.