Last night I saw Jackass: The Movie. It has certain redeeming qualities, such as when a guy puts an electric muscle stimulator on his gooch (the area between the scrotum and anus). Some of it's unnecessary and not all that funny, like giving yourself paper cuts in the webs of your hands and feet and getting shot in the gut with a beanbag gun.
A lot of people don't understand why this kind of masochism is so successful.
Our society has become convinced by the media that they live in an urban jungle hell. Peoples' careers even thrive on the misperception that the city is a cruel, bloody place (hence the entire rap movement) and millions of people die worldwide through genocide and mass murder.
In contrast with all the real violence in the world, Jackass seems cute. Maybe that's why it's socially acceptable now. The generations (my generation and the nintendo generation, as my brother puts it) that enjoy this kind of thing have been brought up under the concept that you should fear your neighbors. We've been fed so many images of horrible things that even our entertainment parallels it. We're given violent video games, violent movies and frantically-paced television. Jackass is rather mild compared to Kosovo or Afghanistan.
And people still wonder why shooting fireworks out of your ass is funny. You laughed at the Three Stooges. You tell me.