> that doesn't give you a free pass to not get arrested when you do break another law
This is covered in the article. Part of the program, after 'boxing in' the protesters, is to indiscriminately arrest everyone regardless of any crimes committed. Charges will be handed off later.
This is a distant relative of the 'I've got nothing to hide' argument in favor of surveillance. In effect, it looks like just being there is enough to get arrested - and this is ignoring the fact that you may actually try to defend yourself when being pushed and prevented from leaving by armed police, maybe while breathing in some tear gas or pepper spray. You may even consider that the goal of the whole operation is to stir up violence, so that everyone has a reason to be arrested...