[sgbuffett]

Where is the video on that Cheer case which I have not seen? I only see a couple of videos posted by you on US police. You wrote so much craps for what? I inferred from reading some posts that this case involved a simple case of police officer asking the Cheer employee to identify himself by showing his ID because he appeared suspicious, and he was reluctant to cooperate for unknown reasons.  
What is so difficult, or harm will happen to him to show the police his IC so that the law enforcement officer can move on? All it takes is just a few minutes and no delay will incur to his "busy" work as you invented with your creative imagination. He is obviously trying to be a smart ass or trying to be funny by obstructing the law enforcement work by questioning and probably delaying the police in pursuing of the real criminal who might escape because of his hindrance. ....

The question is not whether jts a simple thing but whether they have right to it and what is legal requirement 

You said you have not seen the video so you are just jumping into conclusions.