Persons Unknown and other known unknowns

8th July 2019

Michael Walsh’s latest article sets out how to obtain urgent injunctions against urban explorers and other trespassers. Michael is regularly instructed by landowners to obtain urgent injunctions or possession orders against trespassers.  His expertise and successful track record in doing so is recognised in the Chambers & Partners UK Bar Guide.

Trespassing comes in many guises: fly-tipping, squatting or political and environmental protesting to name a few. Recently there has been a proliferation of urban exploration, which involves trespassing on high-profile sites without going into possession of the land.

Recent examples include trespassers on the O2 Arena (Ansco Arena Ltd v Law and others[2019] 3 WLUK 135) and Canary Wharf (Canary Wharf Investment Ltd v Brewer and others [2018] EWHC 1760 (QB)). In the O2 Arena case, the urban explorers not only climbed onto the iconic roof of the arena, but they posted their exploits on social media.

This is common to cases involving such trespassers, with the attraction of notoriety and commercial gain on Instagram and YouTube. This is encouraging them to take increasingly daring risks. Some videos on YouTube will show trespassers climbing to the top of the jibs of cranes, without ropes or harnesses, to enable them to broadcast the climb on their social media channels.

In addition to obtaining an injunction restraining the trespass, the claimant also obtained a mandatory injunction ordering the defendants to remove footage from social media platforms. The court accepted that the encouragement, whether deliberate or not, of others to trespass on land was itself a nuisance. Further, if it had ever been a requirement of a claim in nuisance that the harm must emanate from some other land occupied by the tortfeasor or on which the nuisance was created, that was no longer a requirement. The tort focuses on the injury to the amenity of the landowner. The biggest obstacle to obtaining orders to remove video from social media is going to be evidence that it is inciting others to do so. In this regard, claimants are only likely to obtain orders in cases involving high profile landmarks that draw others to attempt similar acts of trespass.

Persons unknown

Obtaining a quia timet injunction against these trespassers can present difficulties as it is often hard to identify them by name. Recently, the courts have been stricter when granting injunctions against “persons unknown” and require the claimant to identify the class of persons unknown with greater specificity.

Earlier this year the Supreme Court decided Cameron v Liverpool Victoria Insurance Co Ltd [2019] UKSC 6, in which it held it was not permissible to sue an unknown driver of a car which had collided with the claimant’s car for the purpose of then suing that unknown driver’s insurance company. Giving the judgment of the court, Lord Sumption stated the critical question was what (if any) circumstances could jurisdiction be exercised against persons who cannot be named. He answered this by reference to two categories of persons unknown:

“It is necessary to distinguish between two kinds of case in which the defendant cannot be named, to which different considerations apply. The first category comprises anonymous defendants who are identifiable but whose names are unknown. Squatters occupying a property are, for example, identifiable by their location, but cannot be named.

“The second category comprises defendants, such as most hit-and-run drivers, who are not only anonymous but cannot even be identified. The distinction is that in the first category the defendant is described in a way that makes it possible in principle to locate or communicate with him, and to know without further inquiry whether he is the same as the person described in the claim form, whereas in the second category it is not.”

Typically, urban explorers, environmental protesters or other trespassers onto land will fall into the first category of persons unknown. They are usually identifiable by the tort committed in respect of a definable property, but their names are unknown.

In Boyd v Ineos Upstream Ltd [2019] EWCA Civ 515, the Court of Appeal reviewed the authorities on granting injunctions against persons unknown and gave useful guidance on when quia timet injunctions should be granted:

“there must be a sufficiently real and imminent risk of a tort being committed to justify quia timet relief;

it is impossible to name the persons who are likely to commit the tort unless restrained;

it is possible to give effective notice of the injunction and for the method of such notice to be set out in the order;

the terms of the injunction must correspond to threatened tort and not be so wide that they prohibit lawful conduct;

the terms of the injunction must be sufficiently clear and precise as to enable persons potentially affected to know what they must not do; and the injunction should have clear geographical and temporal limits.”

Bringing claims

Claimants seeking interim and permanent injunctions against urban explorers must take care about how persons unknown are described in the claim form. The description should not use a legal conclusion such as is implicit in the use of the word “trespass”. Words such as “intending” should also be avoided because they depend on the subjective intention of the individual which is susceptible to change (see Hampshire Waste Services Ltd and others v Persons Unknown [2003] EWHC 1738 (Ch)).

Claimants should use neutral language that corresponds to the threatened tort and does not unwittingly bring persons with lawful authority, such as emergency services, within the ambit of the injunction. In RGCM Ltd v Lockwood and others (2019, unreported) the claimant restrained entry onto building sites by urban explorers who climbed the crane jib and filmed it for use on social media. In that case the High Court granted an injunction against persons unknown described as: “Persons Unknown entering or remaining on [the property] without the consent of the Claimant or other lawful authority.”

Taking care to follow the guidance given in Boyd will protect claimants against delay in obtaining an injunction to stop what is often extremely dangerous behaviour.

This article was first published in the Estates Gazette.

Michael Walsh is a barrister at Tanfield Chambers and can be instructed in urgent injunctions or possession claims against urban explorers and other trespassers by calling Billy Forecast on 020 7421 5300.


This content is provided free of charge for information purposes only. It does not constitute legal advice and should not be relied on as such. No responsibility for the accuracy and/ or correctness of the information and commentary set out in the article, or for any consequences of relying on it, is assumed or accepted by any member of Chambers or by Chambers as a whole.



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