"can", "should" and "need" sadly have very different meanings. If you get stopped, have an item confiscated and "let go your marry way" - as have happened - I'd just play along.
Anyway, I am not here to win any arguments. This is my advise based on active participation in the knife community and the experiences I've had. You ofcourse need to make your mind up and act based upon your own sources, opinions and experiences.