This is a clear violation of the 1st Amendment, very much unlike yelling "Fire!" in a crowded theater (which is the example everyone wants to use to defend this silliness).

You should expect to be in trouble if you make a serious statement, like "I have a bomb in my luggage!" but clearly joking, saying, "It's not like I have a bomb, after all," or "What do you think that is? A bomb?" should not cause the reactions it does.