The Intervasion of the UK was a 1994 electronic civil disobedience and collective action against John Major's Criminal Justice Bill which sought to outlaw outdoor dance festivals and "music with a repetitive beat".
Launched by a group called The Zippies from San Francisco's 181 Club on Guy Fawkes Day, November 5, 1994, it resulted in government websites going down for at least a week.
Section 65 allowed any uniformed constable who believes a person is on their way to a rave within a 5-mile (8.0 km) radius to stop them and direct them away from the area; "non-compliant citizens may be subject to a maximum fine not exceeding level 3 on the standard scale (£1000)".
[This quote needs a citation] The Zippies sought to jam the mailboxes of UK politicians associated with the Bill in order to bring their attention to the issue of natural justice involving basic rights and freedoms.
Thus jamming mailboxes with email and large file attachments defeated the purpose of the exercise which was essentially an early form of hacktivism.