The tents, tarps and protest signs stretch south along the ICE building, forming an ad hoc main street along a bike path and trolley tracks, protected at both ends by barricades made from wooden pallets. Organizers say the walls are intended as protection against anyone who would use a vehicle as a weapon against protesters—a frightening plausible scenario to antifascist demonstrators who have seen similar attacks from Charlottesville, Va. to Vancouver, Wash.