When President Bush's two-day ultimatum to Saddam Hussein expired Wednesday, a parallel deadline passed for anti-war protesters in San Francisco. Three days earlier, a very loose coalition of antiwar groups had announced their intention to "shut down" the city's financial district the morning after hostilities began. After weeks of planning, protesters occupied several intersections on the city's main commercial thoroughfare, Market Street, by seven am Thusday morning. Most of the protesters moved in small groups, doing their best to avoid confrontation with police, who were out in dramatic force at some locations, but totally absent in others. The protesters had a game plan: a few would step into a busy intersection, stopping traffic, while others pulled debris -- usually metal newspaper vending boxes -- into the street. Most of the blockades were short-lived; protesters usually removed the debris after ten or fifteen minutes. When police did catch up with the activists, they formed phalanxes across the street, advancing to disperse the crowd. The protesters scattered, moving quickly to another intersection and repeating their efforts. Not everyone tried to stay a step ahead of the police, however. Shortly before 7 a.m., several dozen activists locked themselves together in two ranks across Market Street. They formed a human chain, their arms sheathed in heavy pipe, their hands linked with plastic zip-ties. By the end of the day, hundreds had been arrested. Though police were generally not quick to use force, the presence of officers in riot gear initially gave the scene a tense edge. This quickly became somewhat forced, however, as arrests began and police seemed, with few exceptions, to be limiting their use of force. For their parts, the protesters shouted encouragement to each other, and sometimes complained loudly when removed. More than anything, the mood on Market Street was one of confusion: protestsers asking each other where to go next, cops waiting for orders, and firefighters puzzling over how to get a limp twenty year old's shackled hands pried apart without breaking anyone's arm. And no one was going anywhere on a bus, that was for sure. Marc Herman is a San Francisco-based freelance journalist whose work has appeared in Mother Jones, Spin, Harper's, and other publications. His first book, Searching for El Dorado, was published in February.