Not enough information. Does he glue himself to the internet because he is too wired up to sleep? Or does an addiction to the internet keep him from going to bed? In any case, why is he allowed so much time on the internet?
If he is an adolescent, I'm wondering why you can not turn the computer off. He does not need one in his room and if it is out of his room, you have control.
The internet can be quite addicting and you must take that seriously. People avoid "real" relationships for those created on the internet. It is a way of avoiding the world. I think I'd have very clear boundaries/time constraints for the internet, invest in some solid therapy for him, and help him explore other avenues for socializing. Good luck.