A masked reveller parades through the streets on the first day of the carnival season in Lucerne, Switzerland, 12 February 2015. In the background the well known Kappellbruecke bridge. (Photo by Alexandra Wey/EPA)

A Palestinian woman paints a mural, depicting a masked Palestinian holding a knife, in support of Palestinians committing stabbing attacks against Israelis, in Rafah in the southern Gaza Strip November 3, 2015. (Photo by Ibraheem Abu Mustafa/Reuters)

Street musicians with their faces covered with animal masks play to earn some money in central Vienna, Austria, November 8, 2015. (Photo by Vasily Fedosenko/Reuters)

A Chinese tourist wears a mask as she arrives at Suvarnabhumi Airport during a welcome ceremony of Chinese Lunar New Year travellers in Bangkok, Thailand on January 22, 2020. (Photo by Soe Zeya Tun/Reuters)

Ostriches wear masks as they are transported by a truck for relocation in Zhengzhou, Henan Province, China, August 8, 2016. (Photo by Reuters/Stringer)

A masked reveller poses in San Marco Piazza during the Venice Carnival, January 30, 2016. (Photo by Alessandro Bianchi/Reuters)

Rugby Union, Hong Kong Sevens, Hong Kong Stadium on April 9, 2016: A fan wearing a mask is hugged. (Photo by Bobby Yip/Reuters)