Obsessions are not healthy. Drinking and drugs can harm your mind, but the obsessions with modern American culture may do more damage simply because most of those afflicted with them are not treated this way. Compared to other obsessions, those who play with computers have the least favorable view, when their obsessions may not be that bad.
For example which would be more acceptable to a wider range of people: Going over to a friend’s house to whack some lazy peons into action in a video game like World of Warcraft, or putting on your Niners jersey and going over to your friend’s house to play Madden ’08? The second option is far more socially acceptable, but both require the same amount of investment in your life. Forming a guild in WoW is really not that different from forming a fantasy football league.
Both of these things require a massive investment of time and effort. Both of these things involve a person delving into a world full of arcane rules, and tactics foreign to many other people. Yet those who play WoW are looked down on, while those who dive headfirst into sports are not. The universe of sports is just as violent as the one of video games.
Searching Wikipedia for an item like soccer hooliganism or sports violence will get you to an incredibly long list of incidents, but the same search for video games will not get you as long a list. This is due to the shorter life of the video games industry. Violence happens in both worlds, yet video games get more press for it. A regulatory agency, the ESRB, has been set up to rate video games on their suitability for children. There is no sport I know of that you have to show an ID to view.
Despite the violence that may come from either of these things, both of them are a waste of time. They serve to distract and insulate us from the outside world, through providing an outlet for aggressive and constructive emotions, by channeling them into effort for things such as new plays and tactics. The more addicted we get to these things the more we risk falling like the Romans into a pit of sensationalism.