Actually, the most disturbing part of the article is right here:
This terrifies Bush opponents, who worry that violence on the streets of New York will help the Republicans by making them look like Middle American moderates besieged by nutty radicals. They note that the Chicago '68 debacle helped cement Richard Nixon's reputation as the law-and-order candidate.
One of the organizers thinks that ordinary New Yorkers will see the protests and join in. I can guarantee that I won't be among them. I stood on the fringe of the anti-war protest in Washington Square Park in March 2003 and had zero desire to get any closer. When i saw police in riot gear run past I went straight home until the whole thing was over. If the convention week is anything like that anti-war protest, it actually won't be that bad -- there were only a few arrests in an otherwise peaceful crowd. Unfortunately, based on this article and some other things I've read and heard, I think the outrage at the Bush administration is at such a high level that this time protests will be long, loud, and combative.