Since the 2015 hack of millions of government files, insiders claim agents have been more determined to identify potential internal threats Among ways to determine threats is to find if an employee has tried to beat a polygraph test by changing their body language to thwart the result The bureau has apparently stepped up its interrogation of employees, specifically those with Chinese backgrounds, after last year’s hack of millions of government personnel files that was traced back to Chinese hackers. Employees must submit to routine polygraphs every five years.