If you are a parent, or even a teenager  (though what you’re doing here, reading this goodness only knows)  then I have a key piece of advice for you.

This weekend, watch the film Trust.  Produced and directed by David Schwimmer, the geeky one in Friends who almost but never quite got his woman, it is essential viewing.

If your teenager spends hours glued to their phone or buried in their rooms online on a laptop or PC, “chatting” or doing “nothing” then you have to see this film.  Because instead of just shrugging and getting on with the dishes, or smiling to yourself that you know where yours are and what they are doing, this film will show you just how at risk they really are.

Sadly, Trust didn’t get a wide cinema release this summer, so you’ll need to go and buy the DVD.  That’s because it had no major distribution backing and also because it did not fit easily into categorisation.  Indeed, David Schwimmer struggled to get a low enough rating for the film so young teens could get to see it (he failed in the end).  It contains some harrowing scenes, it has quite a lot of swearing, and also some violence.  It’s a hard film to watch, especially for parents, but it’s a must see.

The story centres on a 14 year old girl who meets a boy online who turns out to be a wolf in teenage clothing.  He is actually a 35 year old paedophile who grooms the naive and gauche 14 year old, meets her and sexually abuses her.  The film shows how it is done – how easily it is done – and then the fall-out from what happens.  Abuse has a terrible impact on children, and on whole families, whether perpetrated from within or outside their nest: at times, you will be watching through your fingers.

But the film also shows how pervasive technology is in our lives and also how sexualised our society has become.  And this is the hard bit for parents – the film also demonstrates how easy it is for us to take our eyes off the ball, to be too caught up in stuff to truly give time and space to our teenagers.

Anyone who has ever raised one will know what a tough gig that is.  They go from being engaging, enchanting creatures to cuckoos.  Too big, too awkward for themselves, never mind us, normative behaviour deserts them.  Especially speech and sharing.  Oh and being tidy, coherent, thoughtful and appreciative.  You are either glowered or grunted at.  If you are really lucky you get the odd contemptuous look.  But you have to stick with it and on the odd occasion when they actually want to communicate, drop everything and listen.

We also need to understand that the internet is simply a place.  Somewhere they go to hang out.  And if they were doing that physically, you’d want to know where they were going and who they were going with.  Parents need to start asking the same kind of questions – and ignoring the one word “nowhere” and “no-one” answers – when their teenagers go online.

Because just as when they head out the door, everytime they go onto an online space there are potential risks.  And while you cannot be there with them – god forbid, you’d want to – you should at least attempt to satisfy yourself you know where they are going and with whom.

Of course, knowing these things isn’t enough.  We also have to instil in our young people an ability to keep themselves safe.  Resilience had gone out of fashion in child care lingo but actually it is vital.  We cannot always protect our children – including the ones we don’t know – and we need to give them the skills to keep themselves safe.  Knowing how to sniff out trouble, knowing how to avoid it, and knowing how to handle it when it comes knocking are key essential life skills.

Watch the film and afterwards, go find some advice on what you as a parent should be doing to keep your child safe.  You’ll find it online, naturally.