The internet has revolutionised communications and the way many of us live our lives. But for some, it seems, the opportunities offered by the web, can become a compulsion to stay online.
That kind of behaviour is becoming so widespread, that it has been given a name: internet addiction disorder - and clinics have been set up across Europe, America and Asia, to treat it.
Some mental health professionals now believe it has become such a serious health issue, that they want to see internet addiction disorder added to the official reference book for recognised mental illnesses.
Vera Frankl reports on a 21st Century affliction.