Members of Saudi security forces take part in a military parade in preparation for the annual Haj pilgrimage in the holy city of Mecca September 17, 2015. (Photo by Ahmad Masood/Reuters)

A Wiesel combat vehicle of the German Bundeswehr armed forces takes part in a demonstration for visitors prior to military exercises on September 28, 2011 near Munster, Germany. The Bundeswehr has instituted far-reaching changes in recent years, including an end to compulsory military service. (Photo by Sean Gallup/Getty Images)

Pfc. Sebastian Rodriguez, machine gunner, Weapons Platoon, Lima Company, 3rd Battalion, 3rd Marine Regiment, Marine Rotational Force – Darwin, fires an M240 machine gun during a night squad-attack exercise, here, May 22, 2013. (Photo by Sgt. Sarah Fiocco/U.S. Marines)

A woman is tattooed during the Great British Tattoo Show in Alexandra Palace in north London, Britain May 23, 2015. (Photo by Neil Hall/Reuters)

A woman with a Japanese style full back body tattoo at the 12th London International Tattoo Convention, which opened today in Tobacco Dock, east London on September 23, 2016. The show features over 400 of the world's finest, most prestigious and elite tattoo artists as well as a showcasing alternative culture in the form of piercing, burlesque and the Miss Pin Up UK competition. Around 20,000 people will attend over the weekend. (Photo by Michael Preston/Alamy Live News)

Mary Jose Cristerna, a Mexican known as The Vampire Woman, poses for the public to take portraits of her during the annual Venezuela Tattoo International Expo in Caracas, Venezuela, Thursday, January 29, 2015. Tattoo artists from around the world are gathering for the four-day event that also includes under the skin implants and body piercing. (Photo by Ariana Cubillos/AP Photo)

An artist draws a tattoo on a woman's arm during a tattoo convention in Ljubljana April 18, 2015. (Photo by Srdjan Zivulovic/Reuters)