Why Is Sex Such a Taboo?

Vietnam is having Paris Hilton moment which is actually not true at all since the star of the sex video in this case was already a celebrity. And, instead of launching a career, it has ended hers. And Hoang Thuy Linh is actually very pretty and not the result of years of plastic surgery and millions of dollars in carefully planned publicity.

But still, why is there this awful taboo against sex? Every single person on the planet has it or wants it, what is the big friggin' deal (pun intended)?

How warped is our value system that violence is broadcast on every news channel all day every day but sex is hidden away and treated like the dirtiest thing ever?