Unfortunately there is only so much that Blizzard can control and there are other external ways of cheating that the company simply cannot do anything about, and that is match-fixing. So far things have been pretty good, at least until now where over in South Korea, the player manager and coach of local team Luminous Solar has been booked for alleged match-fixing.
For those unfamiliar with match-fixing, this is happened in the past with all kinds of sports, such as football, boxing, and so on, where one team or one player is paid off to purposely lose the match so that the people betting on the opponent, usually an underdog where the odds are stacked against them, will be able to win a huge payout.
In the case of Overwatch, OGN who organized the event has since handed out lifetime bans against those who are involved. Note that the bans are only for OGN events but given the stain on the team and the people involved, we wouldn’t be surprised if more eSports platforms would follow suit as well.