The ‘Persons Unknown’ Jurisdiction
‘The “Persons Unknown” Jurisdiction’ refers to the power of the Court to grant an order against ‘Persons Unknown’: persons liable to suit by description, as long as that description is ‘sufficiently certain…to identify both those who are included and those who are not’ (Bloomsbury Publishing Group Ltd v News Group Newspapers Ltd  EWHC 1205 (Ch)).
The jurisdiction has expanded and developed over the years, and this has not been without its challenges. In particular, two issues have arisen: the definition of ‘Persons Unknown’—as laid down in Bloomsbury—is inherently uncertain (‘the Definitional Issue’). And secondly, the scope of the jurisdiction is unclear (‘the Scope Issue’). The fact that the definition can be uncertain, but the scope of the order can be wide, creates some tension, particularly when it comes to the knowledge of a person of the order made against them, and whether valid service can occur without the person being aware of this fact. Is it really possible to be in breach of a Court order, and hence potentially in contempt of Court and liable for fines and potential imprisonment, that you don’t know anything about?
The Definitional Issue: who can constitute ‘Persons Unknown’?
Although the definition in Bloomsbury—anyone, as long as one can separate those who are from those who are not—offers little guidance, it is now clear there are three categories of Persons Unknown. (1) Those who are identifiable but whose names are unknown (e.g. identified by location or by reference to a photograph) (C1); (2) those who are not anonymous but cannot even be identified (e.g. most hit and run drivers) (C2); and (3) “newcomers”: a challenging category of persons who are not within the definition of ‘Persons Unknown’ at the time the Court made the order but who subsequently fall within that definition (because, for instance, they commit acts prohibited by the order) (C3). It is this latter category that causes the most difficultly where service and knowledge are concerned.
The Scope Issue: what form can an order take; is there a requirement of subjective knowledge for valid service?
As is well-known, the Court extended this jurisdiction to world-wide freezing injunctions in CMOC v Persons Unknown  EWHC 2230 (Comm), which has been applied subsequently in many cases. We therefore turn straight to the second – arguably, more important question: is there a requirement for subjective knowledge of the order on the part of the defendant for there to have been valid ‘service’?
It seems relatively clear that for C1 and C2 defendants, that there is no such subjective knowledge requirement (Cuciurean v Secretary of State for Transport  EWHC 2614 (Ch)).
The situation in relation to newcomers (C3) is more complicated, however, the current position appears to be that subjective knowledge of the order is a requirement for valid service on newcomers: ‘such injunctions…appl[y] in their full force to newcomers with knowledge of them.’ (Barking and Dagenham LBC v Persons Unknown  EWCA Civ 13)
Nicklin J in MBR Acres Ltd v McGivern  EWHC 2072 (QB)  said that he did ‘not find it easy to reconcile’ the differing positions. At first blush, it is difficult to see why subjective knowledge of the order is required for C3 defendants, but not for C1 and C2 defendants, and we hope that this issue is one that resurfaces in Court again for further consideration. One argument for the distinction could be that C1 and C2 defendants are more likely to be aware of their wrongdoing, even if they are not subjectively aware of the order, for example in the case of protestors, the police may have been called, and those people may have been issued with warnings. However, this distinction makes less practical sense when applied to the more far-reaching corners of the Persons Unknown jurisdiction. For example – how can it be said that whether an unknown fraudster (identifiable – for example – by reference to bank account details) needs to have subjective knowledge of a freezing injunction before they are in contempt of Court for such a breach comes down to the timing of the order in the context of when they received the funds. It remains to be seen how notification of service considerations will be applied in these contexts of the Persons Unknown jurisdiction.