Is there really such a thing as "bad language"?

Is there really such a thing as "bad language"?
What is it that makes some words "bad" as opposed to not "bad"?
Is bad language really bad or is it just a social contrivance?
When does protecting the public from being offended cross the line into censorship, blandness, and oppression.
Are forces for censorship within the the BBC using the Russell Brand / Johnathan Ross / Georgina Baillie / Andrew and Melody Sachs affair as an opportunity to impose harsh censorship on live freedom of speech?
Or not?
Should we be scared of the increasing level of censorship and political correctness?
Or not?
Isn't there a difference between using words which are considered in and of themselves to be inately offensive and being nasty or cruel or unkind or defamatory to or about a person?