Slavoj Žižek gave a talk at Powell's in Portland in 2008 wherein he addressed the ideology behind censorship. His basic point is that censorship does not really save the people from anything, because it is often clear what is being censored (e.g. an intimate scene in a film being replaced by a fade-out). Rather, he argues that there is some "other" which is actually being protected from seeing the vulgar material. It is a thought-provoking point.
I noticed this exact same phenomenon in how dirty language is bleeped and blurred from popular entertainment. Most times, given the context, it is obvious which bad word is being said, in spite of the sound being covered up. Sometimes the bleep leaves the beginning and ending sounds in tact, so that there can be no doubt what the offensive word is. And in some even more amazing cases, the word can actually be spelled (e.g. "foxtrot uniform charlie kilo") and pass censorship. That is, only the very naive (i.e. nobody) are protected by such censorship. So why do the censors continue in bleeping, in spite of the fact that everyone still knows what was said? It is a totally futile exercise, and yet it is still carried out.