detective2In the case of Hayes v Willoughby, heard in the Supreme Court last month (you can read Isobel Williams’ post on the proceedings here), the Court was called upon to clarify the scope of the defence against harassment outlined in s 1 (3) (a) of the Protection Against Harassment Act 1997. The section provides a defence for conduct that might otherwise be harassment if it was pursued with ‘the sole purpose of preventing or detecting crime.’ There is also a defence under s 1 (3) (c) if in the particular circumstances the pursuit of the course of conduct was reasonable.


Mr Willoughby alleged that his former employer, Mr Hayes, had been guilty of a number of offences of fraud and embezzlement. He therefore pursued, in the words of the judge at first instance, “a lengthy and persistent campaign of correspondence and investigation” with various law enforcement agencies between 2002 and 2009. He entered into correspondence with the Inland Revenue, Customs & Excise, the Criminal Investigation Branch of the DTI, Companies House and several different police forces. Mr Willoughby continued his correspondence despite authorities concluding upon investigation that there was no evidence to support Mr Willoughby’s allegations.

Previous Decisions

At first instance His Honour Judge Moloney QC concluded that the course of conduct exceeded “even the widest limits of reasonableness and became unreasonable and excessive”. He ruled however that Mr Willoughby has established a statutory defence as under s 1(3)(a). Mr Willoughby had a genuine belief or strong, sincere and reasonably based suspicion that the claimant had been guilty of fraud, false accounting, or tax evasion and that that was sufficient to amount to a defence. HHJ Moloney QC concluded that, in the light of the reference to a test of reasonableness in section 1(3)(c), Parliament did not intend that it was necessary for a defendant to justify his conduct, for the purposes of section 1(3)(a), as reasonable. The consequence was that the defence applies even in the case of a schizophrenic under the delusion that someone is about to commit murder. It was this construction that persuaded the judge to hold that Mr Willoughby was not liable despite the fact that his conduct was unreasonable and excessive.

The Court of Appeal overturned the decision and ruled that s 1(3)(a) is confined to a course of conduct the purpose of which is preventing or detecting crime. There is no reason to protect a defendant whose course of conduct constitutes harassment because one of the purposes is the prevention or detection of crime, unless his course of conduct was reasonable. If a defendant can do no more than show that the course of conduct has been pursued for a number of purposes, only one of which is preventing or detecting crime, he will have failed to prove that the purpose was preventing or detecting crime and he will fall outside the scope of its protection. The defendant must then show that the course of conduct was reasonable, under s 1(3)(c). A finding that the campaign was misconceived or became unreasonable does affect the defence: such a finding would make it highly unlikely, if not impossible, for anyone pursuing such a campaign to show that the purpose of the course of conduct came within the sub-section.


It therefore falls to the Supreme Court to provide some welcome clarity to the scope of the defence. The reasoning of the Court of Appeal appears persuasive, in particular the observation that, “the defence: ?“is not designed to enable any Tom, Dick or Harry to set himself up as a vigilante and harass his neighbours under the guise of preventing or detecting crime” (approved in Callaghan v Independent News and Media Limited [2009] NIQB 1). A vigilante may profess a purpose within section 1(3)(a) which is belied by the nature, extent and duration of the course of conduct he pursues.” It will be interesting to see which approach the Supreme Court favours.