Mr Willoughby is a former employee of one of Mr Hayes' companies. After the men fell out, in 2002, Willoughby began a campaign of harassment against Hayes, writing letters to the police, the Official Receiver and the Department of Trade and Industry alleging, among other things, that his former employer was an embezzler and that he had committed tax fraud. Mr Hayes was investigated by these bodies and no factual basis to the allegations was found. Willoughby nevertheless continued his campaign. The Protection from Harassment Act 1997 makes harassment both a civil wrong and a criminal offence. S.1 (3) of the Act, however, makes it is a defence for a person to show

(a) that his course of conduct