The Tea Partiers were told to stay on the sidewalks while the riot squad marched in formation down the street and took their positions, in the street. Their tactic is to make a rigid demand of the protesters and, when one of them, does not comply with the demand, that becomes the pretext to move the entire group out. I can see a strategy here. If there were plants in the group, it would be easy for a few to them to step out into the street; causing a crackdown on the whole group.
That’s most likely the case, although per by earlier post, few will admit to it.