I think questions at a border don&#x27;t really fall under the fifth, as you&#x27;re submitting to them voluntarily because you want to get in the country. You can refuse to answer any question, of course, but then the border agents can refuse to let you into the country.<p>I&#x27;m not sure if the goal is solely to stop &quot;truly bad guys&quot; who want to bring down a plane from getting on it, but rather make a note of anyone who might be traveling under false pretenses for any number of reasons.