Nobody said it would be a crime. This sounds like an effective tool in determining who should be more intensely screened before being allowed to board or who may be bumped to a later flight while a background check is performed. No arrest. I think it is a good idea if it works as described.
Come come dont be silly... you might have sweaty palms because thats how you are, or you might be worried about your kid whos been in an accident youre flying out to see, or about a big business meeting coming up... good grief it could be nigh anything.