In KKK's case.. - I think it's neither he wants to directly do it to others or he has the intention to let others notice it. I think, as others already mentioned, it was more of a mindless reaction which perhaps could be a result of his habit or tendency to give such reaction when he's frustrated. The camera, just so happened, caught him in the act. - Concur. This has been blown up way more than it really should be..