The movie is about a bunch of bored rich kids in L.A. who for some reason have this need to act all tough and trash-talk (they call themselves "wiggers" - you can start laughing now). The movie focuses on Allison (Hathaway) and her friend Emily (Phillips) who take it further than anyone by "befriending" a gang in east L.A. Then about 30 minutes into the end they want to join the gang, one of them yells "rape" and the white rich boyfriends who also act like wanna-be gangsters show up with guns. And that's about it.
Now the movie really isn't as bad as it sounds in itself. Sure, the plot is completely unoriginal, but Anne Hathaway carries the movie and makes it bearable, and she's probably the only one that's believable in this movie, and just to see her perform is worth the watch.
But other than that, it's like a serious version of "Malibu's Most Wanted" from Jamie Kennedy...and they're as believable as him, which makes the movie lose all sorts of credibility. It also has a hint of "Thirteen" and "Crazy/Beautiful" in it, but these 2 movies are in a whole different league than this one.
Other than the fact that it's not very believable (except for Anne Hathaway who is excellent, which has nothing to do with her nude scene, same goes for Bijou Phillips), the problem is that it shies away from the really ugly, harsh reality, especially the end, it's all very sugar-coated and ends way too well for the movie that it's pretending to be. I also didn't appreciate the ending very much because it makes it seem like the movie was completely pointless. No one really learns anything, and at one point there's a shooting, the screen goes black, and you're never told what happened.
All in all, it's a good showcase of Anne Hathaway's acting chops, but that's about it. I'd say it's worth a rental at best.