I am not too old to remember clearing the last three feet to my bed with a leap, snapping my feet beneath the blankets, and curling up tight, dead centre between the margins of the mattress. What exactly lurked beneath my bed I wasn’t sure, but not for a year’s pocket money would I have dangled a toe into the darkness.

My own children are older now than I was then, but I still worry the Bogeyman – and you should too.  He is a man – man-shaped at least – almost without exception.  No longer under the bed, he is as close as the nearest screen.  He might be in early adulthood or middle-aged, but he understands youth culture – new memes and dances, the hot online multiplayer games, the “attention economy” of likes and follows.  He has a strong sexual interest in children – by 14 or 15, they are too old for him.

The Bogeyman loves kids who talk to strangers.  He especially loves kids who post videos or live-stream.  Dancers and gymnasts are his favourites.  At first, he is quick with praise and affection.  He’ll even buy a few hundred new followers for a pre-teen would-be Influencer, or use multiple “peer” personas at once to create social pressure. Methodically, he works his targets up an escalation ladder – a suggestive selfie becomes leverage.  Feeding him makes him meaner. I need a new video when you get home from school, or I show everyone you know what you’ve been doing.

Online offenders – non-contact! – can be far more prolific than “traditional” offenders, with some reaching more than 1,000 children.  Their interactions become semi-scripted, like a telesales agent.  Each child is meeting the Bogeyman for the first time, but he has practised answers for 100 objections.

In computer security, we have a concept of a “threat persona”.  Knowing who you are trying to defend against makes it easier to choose sensible and proportionate countermeasures.

How to Protect Your Children

• Hold out as long as you can before giving your child that first phone
• When the time comes to let them go online, speak to them as frankly as possible about how strangers may approach them (this can be really effective)
• Have your kids use the internet in the more public areas of your home (let the light in!)
• Be aware of which online games and services they are using (let the light in!)
• Do everything you can to make sure they know that if they make a mistake, you will be there, listening and supporting them (the Bogeyman loves isolation)

As a child, I knew how to keep the Bogeyman away – just let a little light in.