The term 'Security' refers to the protection against danger, damage, loss and criminal activity. In London, Security Services are provided by security firms and proprietary security departments that practice the “detect, deter, observe and report" methodology. Security officers are not required to make arrests, but have the authority to make a citizen's arrest, or act as an agent of law enforcement at the request of a police officer, sheriff, and others. A security officer’s primary duty is the prevention and deterrence of crime. Security officers are often trained to perform arrest and control procedures like handcuffing and restraints, operate emergency equipment, perform first aid, etc.