I guess Id have to admit I have an internet problem myself. Just not with an artificial world though. I used to spend hours on Offtopic.com. Its one of the best/biggest forums. I still go on there but limit my activity on there now. I used to stay up til like 5 am in college sometimes on there.

Its just something to do when all your friends are sleeping, doing something else, or working. I used to spend alot of time on the wmd (gun group of OT) section specifically. Kind of like hanging out with a second set of friends online. Also helped that they shared the same interests

That and WWII games online. That can be pretty addicting. I have an extremely aggressive and competitive side (I sometimes think thats testosterone coursing through my vains and not blood)
I too used to play til early in the morning.

Call of Duty series for PS2 and PC are my favs