Of all the possible hobbies in the world, pretending to be a child online in order to snare paedophiles is one of the weirdest.
And yet up and down the countries, squads of men – and it’s nearly always men – are doing just that before assembling in a gang to confront their mark in person.
Last week a group of these would-be vigilantes called Wolf Pack Hunters UK caused chaos in Forfar when they confronted an alleged paedophile in the Angus town.
Similar groups have also carried out several operations in Dundee in recent months.
Groups like Wolf Pack Hunters UK claim they are carrying out a public service, exposing paedophiles and thereby protecting the public from their crimes.
But it is probably equally true to say they enjoy being part of mob that gets to intimidate and bully as much as they do exposing sex offenders.
It’s why these groups post so much of their activity online: they like the publicity and notoriety.
Paedophilia is a heinous crime and these groups often exploit the public’s revulsion at it to indulge in aggressive and threatening behaviour.
Any information about potential criminal activity should be passed to the people best placed to investigate it properly, the police.
Anything else is just an excuse for these vigilantes to swagger through towns and cities across the UK, spreading fear and alarm.
There have already been several cases where these so-called paedophile hunters have targeted the wrong person.
Not only is the victim in these cases likely to be highly alarmed, their reputation in the community they live will be in tatters, even if they are completely innocent.
There is also a real chance these vigilante groups can interfere with surveillance operations that are already underway.
More pertinently, much of the evidence they may gather may not be good enough to support a prosecution.
Publicly shaming an offender – even a genuine one – without proper evidence will inevitably make it harder to secure a conviction further down the line if the perpetrator can argue they have no chance of a fair trial.
Paedophilia is a horrendous crime and no one likes the thought of sex offenders living in their community.
But if we suspend due process to allow mob justice, even without the pitchforks and flaming torches, then we undermine the rule of law completely.