I understand completely, there are times when yes sir, no sir are the best tact to avoid a whole lot of hassle. Believe me, I've learned that the hard way.

Plus that little kicker, "Ignorance of the law is no excuse" and if you question them it's "resisting arrest", "interfering with a police officer in the performance of his duties" or "obstructing justice". Of course my all time number one, with a bullet, is "conspiracy".
Having said all that, sometimes you just have to QUESTION AUTHORITY. Besides, if "you" don't get maced, beaten up and on the 6 o'clock news, how am "I" going to know it's illegal?