Antiwar demonstrators in Chicago are alleging censorship after being told they will be kept away from next month’s NATO summit. On Tuesday, the Secret Service said protesters will be barred from coming within at least two blocks of the site where leaders from NATO countries will meet. The umbrella protest group, the Coalition Against NATO/G-8 War & Poverty Agenda, says the restriction will violate their right to be within sight and sound of summit attendees. Organizers say they are expecting thousands of demonstrators for the opening rally on May 20, the NATO summit’s first day.