In Novartis Pharmaceuticals v Stop Huntingdon Animal Cruelty, Mrs Justice McGowan granted an injunction against “persons unknown” under the Protection from Harassment Act 1997. This was the first time such an injunction was granted against “persons unknown” to restrain possible acts of harassment.
Injunctions against “persons unknown” were developed in the early 2000s, first in copyright cases. In particular, in 2003, in Bloomsbury Publishing group Plc v News Group Newspapers Ltd  EWHC 1205 (Ch), when the fifth in the series of the Harry Potter books, Harry Potter and the Order of the Phoenix, was published, there was a concern on the part of the publishers that certain unknown people had taken a copy of the manuscript and were going to print a bootleg version. The people could not be identified but the court was prepared to grant the injunction.
Two years later, the same thing happened with the next edition of the Harry Potter book. But the time the order of the court was subtly different (sadly there is no written judgment of this decision available). Whilst in 2003, the order related to specific but unidentified persons who had taken the manuscript, this time the order was made against a broader class of unidentified persons, who happened to fit the description of the respondents to the order. As the claimants’ lawyer, David Hooper, said at the time:
“[The injunction] doesn’t just apply to the two named people who were attempting to sell copies of the book. It catches anyone who is in unauthorised possession of ‘Harry Potter and the Half-Blood Prince’. This injunction is much wider in scope than the John Doe order obtained for the previous Harry Potter book.”
This broader application of the “persons unknown” injunction was then used widely in privacy proceedings and has become well established. This is roughly the equivalent of a “John Doe” order in the United States.
However, the decision of Mrs Justice McGowan is the first time a “persons unknown” injunction has been used harassment proceedings. Regrettably, the precise form of the order is not set out in the judgment and it is not clear whether the form of the order is in the narrow or broader form as set out above.
Novartis Pharmaceuticals v Stop Huntingdon Animal Cruelty and others  EWHC 3429 (QB)