text: In this Aug. 18 file photo, people stand near a cloud of tear gas in Ferguson, Mo., during protests for the Aug. 9 shooting of unarmed black 18-year-old Michael Brown by a white police officer. The U.S. government agreed to a police request to shut down several miles of airspace surrounding Ferguson, even though authorities said their purpose was to keep media helicopters away during protests in August, according to recordings of air traffic control conversations obtained by The Associated Press.