Getty Images will bill you thousands to use a photo that belongs to the public. Is that legal?
Dorothea Lange’s photographs of rural life, which she took for a U.S. government agency, are among the most famous images of Depression America: farmers, resettled ex-slaves, inhabitants of migrant camps, homesteaders and landscapes, they tell the story of a nation indomitably facing an uncertain future.
http://www.latimes.com/business/hiltzik/la-fi-hiltzik-getty-photos-20160801-snap-story.html