Just to chime in on this bit, there isn't anything wrong with disobeying a law to raise awareness about a law you deem wrong. It's a cornerstone of civil disobedience.
But...it is imperative that once police officers, or federal agents, etc., declare that they will arrest you, you must comply with them in a peaceful manner. Do as they order explicitly. That way no one gets hurt, and police will (generally) treat someone in a less forceful manner if they are acting in a civilized and respectable manner. Throwing a fit and making a scene on the spot is not the proper way to conduct that kind of protest.
For what it is worth, I also agree that the officers did nothing wrong. The protesters were acting like children instead of adults.