SLANG

I am trying not to use slang so often because I am polite in more cases.If I need to use it, I mostly use it with my friends because they don't correct me and sometimes we aren't aware that we are using it.The problem is when we don't distinguish the difference between the slang and common speech.
I totally agree with statement that definite the slang:"Slang is a kind of language that identify you with the group that you belong to."
I think that every man has his own way of speaking and his own slang.I know that there is queen's language and it is very formal, but queen is also a human being and there is no way that she has never used slang.We have heard that Bush used it in private talks and there is nothing new about it.
I didn't know that slang means a secret language.I think that is more important advantage of it. As we could hear, we can use it in markets or in every kind of institutions where secret codes are needed. So, why don't use slang?Maybe, some of as wants to work in army.Using slang, we can work as secret agents in CIA or White House.Why not?
As long as we use slang in speaking, that is OK, but we have to be careful not to use it in writing. For example, when we say something stupid and we want to correct ourselves, it is easier when we are talking because the written word can be misunderstood. And that is beginning of our problems.
I think that hosts from BBC did a great job by emitting this kind of clip. He made us laugh and that was his aim.I think that he tried not to use the real slang because he didn't call this guy an "asshole" but "douchebag" like that is more polite.I am not surprised by his using of slang because this is a joke and he can use as more of it as he wants.