What Mike MEANT to say was if they asked you for ID, that's your sign it's "official".
Better to err on the side of caution is my motto... sometimes. Yeah I got MB's point, not a tinfoil hatter nor do I consider our officers to be jack booted thugs, just an observation that in general I have in all my years never attracted attention from law enforcement unless they were interested in something I may or may not have done.