Griffiths believes that the first two examples are examples of addiction, and that the remaining examples fall short of meeting the criteria. The first example does not even mention the Internet, however. If this teen is addicted, it is an addiction to computers in general. The second teenager may be "addicted" to science fiction, or even to chatting about science fiction. I'm not sure that you can say that he is addicted to the Internet.
Griffiths' presentation illustrates that there are a variety of problems which sometimes develop related to use of the Internet. I agree that the topic of pathological Internet use needs further study, especially since more and more people are using the Internet.
Using the term "Internet addiction" to describe these problems confuses the issue and oversimplifies a complex area.
I have also reviewed some research which attempts to define both normal and abnormal Internet use. This turns out to be more difficult than you might think.
If you are having a problem with excessive Internet use you may want to see a therapist in person. Online help may be available through A Guide to Online Therapy Services by Martha Ainsworth. Online help is probably not ideal for pathological Internet use since it contributes to even more time online.
Griffiths, Mark. Does internet and computer "addiction" exist?: some case study evidence. Paper presented at the Annual Conference of American Psychological Association, August 1997.