Internet gaming is the work of the Devil! I hate it when people go for hours on end. My SO got so hooked on it, it almost ruined our relationship. He would start in the morning as soon as his feet hit the floor and he would get up at the very last second he had to so he could get to work almost on time.
He discovered I was serious that I would leave him if it did not stop. If someone wants to play for a little while to relax, that is one thing, but having take over your whole life that is something else entirely.
We even have a game that we play together on the playstation. We play while we drink our morning a few days a week. Guitar Player is lots of fun, but it is not going to control my life.
As far as those people "addicted" to their games, I think it was probably that they had something else contributing to that. That sounds very much like people that do crystal meth regularly. They get obsessed with doing something. I knew a girl that tweezed her entire legs. I knew 2 brothers that would constantly sharpen their Buck Knives. They would have to buy another one every couple of weeks they had sharpened the previous ones into something about as wide as 3 flat toothpicks. WEIRD!