"Spies with surveillance agencies in the United States and United Kingdom may have spent time undercover as orcs and blood elves, infiltrating video games like "World of Warcraft" in a hunt for terrorists "hiding in plain sight" online."
I find this very believable for this reason. I had a student in Teen Second life several years a go and he came across a "meeting" of sorts that was obviously something very strange. When he tried to interact with the players they had a way to throw him out and port him other places. It was obviously some sort of strange thing happening. I have no doubt that games are just another way to have "secret" meetings for those who want to hide. That said, it would be hard to tell the difference between those gaming and those doing other things as the games themselves have people plotting and planning so I'm thinking the language used would be hard to separate the real world from the game itself, which, in some ways makes it the perfect way to hide in plain sight.