The Economist (2020-06-13): Birdwatchers' app inspires a field-guide to protesters' symbols
VizPol, developed by researchers at Columbia University, uses machine learning to identify political symbols. Open the app, photograph the banner—or T-shirt, belt-buckle, tattoo or anything else that may contain a logo—and VizPol will tell you whether you are looking at a supporter of Antifa or the Aryan Nations. Most of the 50-plus symbols it recognises belong to the far right, whose insignia tend to be more cryptic and quicker to evolve than those of the left, says Ishaan Jhaveri, one of the app’s developers. But it can also spot left-wing logos, like the encircled arrows of the anti-fascist American Iron Front and the hourglass of Extinction Rebellion.