An offence committed when three or more persons, present together, use or threaten unlawful violence (R v Mahroof (1988) 88 Cr App R 317). The collective conduct must be such as would have caused a reasonable person to fear for his safety, though no-one else need be present. “Violence” includes violent conduct towards property as well as persons and extends to conduct causing or intended to cause injury or damage. It therefore includes throwing a missile at someone though it does not hit him or falls short. The offence is found in the Public Order Act 1986, though it can be committed in private as well as in public places. It replaces the common-law offence of unlawful assembly and is punishable with up to five years' imprisonment and/or a fine. Violent disorder differs from riot in the smaller minimum number of participants, the absence of need to prove community of purpose, and a lesser maximum punishment. As with affray, a person is only guilty if he intended to use or threaten violence or was aware that his conduct might be violent or threaten violence. For this purpose, an intoxicated person is taken to be aware of what a sober person would have been aware. If the police fear that a violent event may take place they may now exercise stop-and-search powers (see power of search).
It is also an offence, punishable with six months' imprisonment and/or a fine, to do any of the following, without legal authority, in order to compel a person to do (or not to do) something he has a right to do (or not to do): use violence towards or intimidate that person, his wife, or children or injure his property; persistently follow him; hide his property or hinder his use of it; watch or beset him or his place of residence, work, or business; or follow him with two or more others in a disorderly manner in a street or road. This offence is aimed mainly at disorderly picketing. However, it is lawful to watch or beset a place (other than a residence) for the sole purpose of peacefully obtaining or communicating information or peacefully persuading any person to work or not to work.