National Guardsmen are put through riot training in Boston's Commonwealth Armory on Friday, October 18, 1974. Massachusetts Gov. Francis W. Sargent called up the guard to quell school violence, but the city has been relatively calm and the guard has remained in the armories. (Photo by JWG/AP Photo)

People mourn next to the body of Muddasir Khan, who was wounded on Tuesday in a clash between people demonstrating for and against a new citizenship law, after he succumbed to his injuries, in a riot affected area in New Delhi, February 27, 2020. (Photo by Adnan Abidi/Reuters)

Riot police wear face masks, as a precautionary measure against the COVID-19 coronavirus, allow a women to cross a cordon after a protest by pro-democracy demonstrators at a shopping mall in Hong Kong on May 9, 2020. (Photo by Isaac Lawrence/AFP Photo)

A member of p*ssy Riot performs in the nationwide Women's March, held after Texas rolled out a near-total ban on abortion procedures and access to abortion-inducing medications, in Austin, Texas, U.S., October 2, 2021. (Photo by Evelyn Hockstein/Reuters)

In this Friday, December 4, 2018 photo, a half sunken cruise ship lays on its side, in the Gulf of Elefsina, west of Athens. Dozens of abandoned cargo and passenger ships lie semi-submerged or completely sunken around the Gulf of Elefsina, near Greece’s major port of Piraeus. Now authorities are beginning to remove the dilapidated ships. Some of them have been there for decades, leaking hazards like oil into the environment and creating a danger to modern shipping. One expert calls the abandoned ships “an environmental bomb”. (Photo by Thanassis Stavrakis/AP Photo)

Lukas Michul, a member of the “dream walker” group jumps from atop the rugged rocks overlooking the azure waters of Navagio beach, one of the Greece's most renowned leisure spots on the popular tourist island of Zakynthos on June 23, 2014. This is rope jumping – part diving, part rock climbing, with a touch of engineering. The aim of the project is to dream jump in 80 places with most ravishing nature and architecture all over the world .They plan to stage their next leaps at a cave complex in Croatia, a French viaduct, skyscrapers in Las Vegas and Johannesburg, and the Grand Canyon. (Photo by Louisa Gouliamaki/AFP Photo)

People lay flowers for and mourn the anti-government protesters who were killed in the past weeks’ clashes with riot police.

A Palestinian demonstrator jumps in the air during clashes with Israeli riot police on May 13, 2011 in the East Jerusalem neighbourhood of Issawiya, Israel. Palestinians began marking the “Nakba” or “catastrophe” which befell them following Israel's establishment in 1948. (Photo by Uriel Sinai/Getty Images)