Animal rights activists covered with fake blood sit on the floor during a protest against the use of animals in research to mark World Day for Animals in Laboratories in central Madrid April 24, 2014. The sign reads, “How many rabbits do your shampoo kill?”. (Photo by Andrea Comas/Reuters)

A woman smokes a mask bong on the final day of Hempfest, Seattle's annual gathering to promote the legalization of marijuana, on August 17, 2014. (Photo by Jordan Stead/Seattlepi.com)

Herring worth millions in exports float dead in Kolgrafafjordur, a small fjord on the northern part of Snaefellsnes peninsula, west Iceland, for the second time in two months. Between 25,000 and 30,000 tons of fish died in December and more now, due to lack of oxygen in the fjord thought to have been caused by a landfill and bridge constructed across the fjord in December 2004. The current export value of the estimated 10,000 tons of herring amounts to $ 9.8 million, according to the newspaper “Morgunbladid”. (Photo by Brynjar Gauti/Associated Press)

A worker holds the head of a fox while killing it with electricity for its fur at a fox farm in Nanzhuang village, Shandong province, China, December 11, 2015. There are over 60 households in the village still raising foxes, raccoon dogs and other animals for the fur trade. China is the world's largest fur producer and exporter, according to state media. (Photo by William Hong/Reuters)

Aerobatic pilot Sean D. Tucker flies in the two-seat Oracle Extra airplane over downtown Chicago skyline, Wednesday, June 8, 2016. Tucker will perform before the start of of the America's Cup World Series racing on Saturday and Sunday. (Photo by Kiichiro Sato/AP Photo)

A visitor falls down as they run away from a wave caused by a tidal bore which surged past a barrier on the banks of Qiantang River, in Hangzhou, Zhejiang province, China, October 28, 2015. (Photo by Reuters/China Daily)

A guard dog in the suburbs of Yakutsk, Russia, considered to be the coldest city in the world, January 2014. (Photo by Amos Chapple/REX Features)