Riot control

Riot control measures are used by law enforcement, military, paramilitary or security forces to control, disperse, and arrest people who are involved in a riot, unlawful demonstration or unlawful protest.

If a riot is both spontaneous and irrational, then actions which cause people to stop and think for a moment (e.g. loud noises or issuing instructions in a calm tone) can be enough to stop it. However, these methods usually fail when there is severe anger with a legitimate cause, or the riot was planned or organized. Riot control personnel have long used less lethal weapons such as batons and whips to disperse crowds and detain rioters. Since the 1980s, riot control officers have also used tear gas, pepper spray, rubber bullets, stun grenades, and electric tasers. In some cases, riot squads may also use Long Range Acoustic Devices, water cannons, armoured fighting vehicles, aerial surveillance, police dogs or mounted police on horses. Persons performing riot control typically wear protective equipment such as riot helmets, face visors, body armor (vests, neck protectors, knee pads, etc.), gas masks and riot shields. Even though riot tactics are effective in controlling crowds, they can also lead to significant psychological effects on both the rioters and the police. Exposure to intense fear, stress, and violence during these confrontations can result in long-term mental health issues, like anxiety, post-traumatic stress disorder (PTSD), and heightened aggression, which can impact the well-being of protesters and police officers.

There have been cases where lethal weapons are used to violently suppress a protest or riot, as in the Tbilisi Massacre, Nika Riots in the Roman Empire, Boston Massacre, Haymarket Massacre, Banana Massacre, Hungarian Revolution of 1956, Kent State Shootings, Soweto Uprising, Sharpeville massacre, Mendiola Massacre, Bloody Sunday (1905), Ponce massacre, Río Piedras massacre, Bloody Sunday (1972), 1989 Tiananmen Square protests, 2017 Venezuelan protests, 2018–2019 Gaza border protests, 2022 Sri Lankan protests, 2022 Kazakh unrest and Mahsa Amini protests.