I heard that recently on the Warcraft 3 part of World Cyber Games they had to disqualify some players because they didn't use the proper client. I think they were using a different platform or something? Well they put up a reminder on their official website: http://www.wcg.com/news/view/510. I don't know about those who are playing or following the event but hopefully there are no future disqualifications. I feel bad for both the players and the org.