The plot, such as it is, is about a bank robbery run by idiots. They end up dismembering somebody because of basically a pun. There's an interminable Jerry Springer bit -- it was probably ten minutes long but it felt like hours -- that has absolutely nothing to do with the plot of the movie. Like, someone thought, "ha ha, I wrote this funny thing about how Jerry Springer is funny, let's just stick that in here too." It is not, of course, funny. At all.
And yet, this movie couldn't decide whether it wanted to be a stupid slapstick comedy, or a bleak look at some fucked up peoples' lives, or a music video, or just an excuse to watch Keira Knightley pout for two hours. They really should have just gone with that last one.