THE case of stalker Roland Der will chill any parent of a teenage child. The Internet and mobile phones have brought innumerable benefits to our modern lives and it would be nigh on impossible to think of doing without them.

But with it there are also dangers and Der is yet another example.

That people like Der exist is not a new phenomenon. But it is the ability they have to insert themselves into their victims’ lives that is the recent development.

According to what Judge Gordon Risius was told, Der contacted the girl on her mobile phone, including by sending her indecent images, plus via Facebook. Her sister and a friend were also contacted by Facebook, with messages turning nasty when his “affection” was not returned.

The terror of this for both the girl and her family is difficult to fully understand. Not only would there have been the dread of physical visits but also the feeling of being at siege from electronic avenues.

Der is the man at fault for this with his twisted and false obsession there could be a relationship.

But it also highlights that families need to be careful about how exposed their children are to lunatics out in the world of social media.