No-one's immune to hacking, and the bigger they are the harder they fall (but more quickly they recover, given the megabucks, etc). Over the weekend, someone manage to slip a knife into World of Warcraft's ribs, finding an exploit that allowed the usually near-invincible NPCs inhabiting the capital cities of Stormwind and Ogrimmar to become as weak as asthmatic kitten (though this was done by by the exploiting players accessing kill commands, not the NPCs actually being weakened). Slaughter inevitably followed.
Anyone accessing the exploit could kill these NPCs, turning these once-proud cities into brutal, high-speed massacres. I wish I had been there.
Here's a look at THE HORROR, THE HORROR. Of course the exploit was quickly identified, fixed and everyone restored to life, but that's not the point. The point is that in a quasi-living game world, even one as over-familiar as World of Warcraft's, surprising, strange things are still possible.
That video via PCG.
In my fondest, most impossible MMO dreams, when World of Warcraft finally starts to wind down in the year 3112, something like this will be officially sanctioned. The in-game NPC rulers will be overthrown, and then players need to work out what to do with a world in anarchy.