There's a chance there was some mirthful laughter at WWE when it was announced that CM Punk had signed with Dana White and the UFC organisation in late-2014. Rather quickly, this could have also turned to annoyance from Vince McMahon and his most trusted lieutenants. The simple reason being that UFC is considered competition by the McMahon family. A long time ago, Vince said that anybody in the television and pay-per-view business was a competitor to his company. Obviously, the rules on that have changed a little due to the less emphasis on traditional PPV from WWE, but many of those thoughts could still remain. Therefore, the fact that Punk left WWE in such acrimonious circumstances then signed for the MMA league would anger McMahon. Even so, it seems a little strong to say that WWE would never do business with Punk again because of this. What this would mean is that Punk has been able to get away with effectively slapping his former employer in the face, at least in the mind of Vince. The reason this one starts the list is that it's something that could potentially come true in the future.