Concerned US park employees hung an upside-down flag—a symbol of distress or national threat—on El Capitan in Yosemite. They did so at a time when evening light illuminates Horsetail Fall, an event known as Firefall, which is a popular occasion for photographers.
“The purpose of this exercise of free speech is to disrupt without violence and draw attention to the fact that public lands in the United States are under attack… Think of it as your public lands on strike.”