An injunction granted by Mr Justice Warby illustrates both the issues arising in respect of obtaining injunctions against “persons unknown” and also the technical difficulties in obtaining injunctions restraining any matter relating to news reporting.
The applicants were Katherine Kerner and her son Jack. They had sustained press attention because in December the husband of Mrs Kerner, Stuart Kerner, had been convicted of two offences of sexual activity with a child in breach of trust. On 22 January, Mrs Kerner had been accosted on her way to school with her son by two photographers, causing her to take refuge in her house. One photographer, it was said, remained outside her house for an hour.
That day she sought an injunction to prevent harassment of her and her son under the Protection from Harassment Act 1997. She did not know the names of the photographers but she sought an injunction using the well-established device of describing the respondents as “persons unknown”.
The injunction sought had two limbs of relief. First, to restrain “harassment by photography or videoing; or by loitering within an exclusion zone of 100m radius from their home; or by knowingly pursuing either of them”. An injunction was granted in respect of this first limb.
Second, to prevent publishing any material identifying Mrs Kerner or her son. This second limb seemed extremely ambitious. While it has been held that, in extreme circumstances, simply the publication of material (for example in a newspaper) can constitute harassment (see for example Thomas v News Group Newspapers Ltd and another  EWCA Civ 1233) it seems unlikely that the court would consider that the publication of any material identifying Mrs Kerner or her son would be harassment and must itself be restrained.
In the event the relief sought in the second limb was not granted on procedural grounds. This was because insufficient steps had been taken to notify the media contrary to the Master of the Rolls’ Practice Guidance  1 WLR 100, which states that respondents and non-parties who are to be served with or otherwise notified of the order are “entitled to advance notice of the application hearing and should be served with a copy of the Application Notice and any supporting documentation before that hearing”.
The application raises interesting questions regarding the ambit of an harassment injunction against unnamed respondents. There are two means by which such an injunction could be said to have effect against unnamed respondents. First, by means of the “persons unknown” device. Second, by means of the potential contra mundum effect of injunctions. But neither principle is straight forward in this context.
Persons unknown injunctions
Injunctions have been granted against “persons unknown” since JK Rowling secured an order in 2003 restraining the circulation of bootleg copies of Harry Potter and the Order of the Phoenix which was just about to be published. However, since then the “persons unknown” device has been used in two different ways. In that order the “person unknown” related to a specific person (or persons) who was carefully described (by reference to his actions).
In 2005, Ms Rowling obtained a further injunction (in an unreported decision) in respect of the next book in the Harry Potter series, Harry Potter and the Half-Blood Prince. This was also granted against “persons unknown”. However, this injunction was crucially different in that it apparently applied to any person who was in unauthorised possession of the new book. That is, instead of applying to a small number of specific if unidentified (at least by name) individuals, it potentially applied to a much larger class of individuals, anyone falling within the description.
The courts have applied such an approach to harassment injunctions. In Novartis Pharmaceuticals UK Ltd and others v Stop Huntingdon Animal Cruelty and others  EWHC 3429 the court granted interim and final injunctions to restrain harassment against a class of unknown persons (in that case animal rights protestors) specified only by a general description (that is “persons who are conducting or may conduct protesting and/or unlawful activities against the claimants”).
In the case of Mrs Kerner, the injunction granted appears to fall within the more limited sense of a persons unknown injunction. That is that the persons unknown were solely the specific unidentified photographers and not any wider group. It may, in theory, on the basis of the approach in Novartis have included other photographers and journalists within the category of the persons unknown using a general description. But that would appear to be a significant step, likely to be fiercely resisted by the media.
Contra mundum effect
There is another means by which injunctions can be held to bind third parties. That is the so-called contra mundum effect most famously seen in the Spycatcher cases by which third parties with notice of an interim (and arguably final) injunction (for example in privacy and breach of confidence cases) can be held in contempt if they breach the injunction’s terms.
But that principle proceeds on the basis that it constitutes a contempt of court to undermine the subject matter of any litigation. While that principle obviously applies in cases involving breach of confidence and privacy, it is not entirely obvious that it can equally apply in respect of harassment, since in harassment cases the focus is on the specific course of conduct in question, not the information disclosed.
So it is not clear whether a third party not comprised within the persons unknown who committed the conduct restrained by the injunction would be in contempt. However, under the contra mundum, they would certainly be taking a risk.
A further interesting issue arose on the return date, on 29 January, when Mr Justice Warby considered the service of the injunction. As of the return date (perhaps unsurprisingly) the claimant had been unable to serve the order on the unknown photographers. These days the courts are reluctant simply to allow an interim order to remain in force effectively in perpetuity without the action underlying it proceeding (which of course it could not do here, without service).
So the judge ordered that if service could not be achieved within three months of the date of the initial hearing, the claimant was required to apply to the court for further directions. This is likely to be an approach adopted for persons unknown injunctions in the future.
Harassment injunctions have been issued before in media cases. For example, in 2012, the comedian and author David Walliams and his wife, Lara Stone, a model, sought and obtained an injunction to restrain paparazzi activity around the time of their wedding.
If harassment injunctions are going to be the cause of action of choice for claimants seeking to restrain the actions of the media, some of these complex issues regarding the effect of such injunctions on persons unknown defendants and third parties may need to be examined.