Put this one in the "well duh" category, but a clinical psychologist and assistant professor at Harvard Medical School says that as many as 40% of World of Warcraft players are addicted to the game.
In an interview with Twitch Guru, Dr. Maressa Orzack claims that excessive video game playing is similar to drug use and gambling in terms of its addictive qualities and says that the gaming industry should be forced to put warning labels on their products in much the same way as cigarettes do.
Personally I knew WoW was addictive the first time I watched the sun come up without even realizing what time is was.
Why stop at warning labels? Why not do tax MMORPG games to death like the government does with all other fun things?