Let's all agree though. People are never perfect. We tend to "screw up" on our behaviour. But bad behaviour over a long period of time is not a beautiful thing. If I get a rude pm, I'll ignore it or reply calmly without attacking them verbally. If they continue acting up, then ignore.
I ended someone's streak and a player pmed me and said you mad? This was out of nowhere so I asked him and he replied with "_k you!"