I am not sure they would even hold an online tourny, as i know winners of event tourny's have to turn their game pack over for inspection. Consider this. You have been having a great time in the GTS, you are traded a hacked turtwig but you don't know it. You raise it, enter it into a tourny, win, and get busted for cheating. With the GTS it is FAR easier to get a hacked pokemon than ever before, and you can get it without wanting it or even knowing it. The only way to prevent this is of course not using the GTS, but then why have the game at all?