I recently wrote an essay (submitted in December; published in June) for the Lincoln’s Inn Student Law Journal, which starts at page 14. It’s about the increasing pursuit of suspected paedophiles by vigilantes. From a legal perspective it’s a vexing problem with boundary questions concerning common law, ECHR rights and statute. It’s also a challenging issue for law-enforcement and policymakers. So-called ‘paedophile hunter’ groups are usually unpleasant obsessives who can jeopardise police investigations; but they also identify a large number of sex offenders (who would otherwise be missed) by spending endless hours sleuthing online under child aliases. Therefore, I argue, it is better to manage rather than prohibit PH groups by licensing their activities and refusing to prosecute targets of unlicensed PH activity.
The Supreme Court has for the first time considered the lawfulness of PH groups in the Scottish case of Sutherland  UKSC 32. In a judgment published on Wednesday the court considered only the issue of ECHR compatibility. In particular, is the Article 8 right to a private life infringed by the state’s use in prosecution of messages sent by the defendant to the PH decoy on bilateral messaging Apps? The Article 8 issue has some of the same contours as the common-law entrapment issue, the focus of my essay, in particular holding the state to a higher standard of probity in the procurement of evidence than a ‘non-state’ agent.
Lord Sales for the unanimous court held that Sutherland’s Article 8 rights were not fatal to his prosecution. His activity said to be protected under Article 8 was not “capable of respect within the scheme of values which the ECHR exists to protect and promote” . Nor did the appellant have a reasonable expectation that the recipient of his messages on Grindr, and later on WhatsApp, would keep them private given their criminal content .
Even if the communication was prima facie protected under Article 8(1), its infringement would have been justified under Article 8(2) “as a measure proportionate to promoting the legitimate objectives of the prevention of disorder or crime and the protection of the rights and freedoms of others”  so long as there was no breach of the Article 6 right to a fair trial , a question where the state/non-state distinction also holds to the benefit of PH groups (contrast Shannon  with Teixera  – page 17).
Consulting my crystal ball, my guess is that the PH problem – and it is a problem, as the quotes and figures cited here illustrate – will be addressed by Parliament before the courts. If not, one must concede that the effect of Sutherland is to kill the Article 8 claim. Alternatively it is possible to imagine a successful claim through Article 6 or common-law entrapment. But that will succeed if, and perhaps only if, the court recognises the significance of modern PH activity. They are not occasional interlopers for whom the target’s prosecution is a secondary or incidental result. Rather they operate on a scale that has overshadowed official investigations and won the tacit approval of police and prosecuting authorities, whatever the latter’s statements to the contrary.