People have suffered from all kinds of addictions through all times. Thats what happens when you have something awesomely fun, like world of warcraft, or sex. We better do something about sex soon, or shit is going to get crazy.
To be fair he joked about the illegal part, however, there has been mmo's around before world of warcraft. But due to the big scope of WOW, it reaches way more persons and thus persons with addictive personalities. I'd still say stuff like farmville and such are way beyond what wow has achieved when it comes to catching…