What is [link|http://dictionary.reference.com/search?q=obscene|"obscene"]?
Why is one thing "obscene" but another is not?
Why are some words [link|http://dictionary.reference.com/search?q=profanity|"profanity"] but other words are acceptable?
The culture you were brought up in influences what you consider "obscene" or "profanity".
The word "fuck" is "obscene" and "profanity".
But burning a child alive is acceptable.
In this culture.
Why? Because this culture is heavily Puritanical.
But violence against children is just peachy. As long as you can "justify" it by the ethics / morality of this culture.
Which is very easy to do.
Those weren't children. They were "collateral damage".
Cover the Reality with the right words and you can abstract it enough to support it.
But "fuck" is a naughty word.
Yet there is not naughty word for killing a child.
But there are lots of nice words for killing a child.