The entire movement is aiming to get corporate money out of politics, and so as the movement gains momentum, politicians are pushing mayors to squash the protests. The police presence has less to do with the behavior of the protestors, than it does with the nature of the entire protest itself. Camps have been raided by the police for simply existing (as opposed to because of violence or crime)--and so of course this is going to cause tension and frustration on the protestors' behalf. If the Tea Party was being targeted by police force as much as OWS simply because of its nature, then I guarantee the arrest rates would be similar.
And I would say that greatest difference of that nature is the difference between state and federal frustration. From what I've gathered, the Tea Party seems to be angry with strictly the federal government--whereas OWS wants change at both the state and federal level. And wealthy governors who profit from coporate donations don't like that...So they pressure mayors to remove the protestors. I know this is specifically true in New York. Govornor Cuomo and Mayor Jennings of Albany planned on raiding Occupy Albany. The DA and police chief, after seeing the true, peaceful nature of the protest, refused.
I wonder how many of the 992 listed in this image actually committed violent acts. If you watch raw footage of the protests, you can see police officers grabbing people left and right, without instigation. Granted, there are a few instigators, but certainly not in scale with the amount of peaceful people arrested.