>>However, using the general criteria used for various other addictions in DSM-IV, one can see how easily the internet addiction can be "diagnosed"<<
It sure does sound like an addictive problem, according to the criteria. Whether or not it can be formally diagnosed (a bonafide diagnostic category with etiological, concurrent, and predictive validity) is a much more tricky scientific issue that has important implications - like, will insurance companies PAY for the treatment of it?