And when they do get genuinely malicious, those people are put in their place rather quickly. There is a big difference between joking around to diffuse a situation, and actual mean, hateful, behavior towards other members. That is never tolerated here.
Some members are just cocky. It's their nature. You learn who they are fairly quickly and you learn to deal with it or ignore it, but they are not directly mean to others. Some people just can't take their criticism and can become offended. You need to learn the difference. Take in everything with an open mind.