Bradley's not just flipping off the crowd. He's presenting a metaphor for how he treats fans of any team who have the unfortunate task of rooting for him to succeed.
Milton Bradley, baseball's Kanye West if Kanye West were even poutier, kind of has a problem with authority. In that he thinks there should be no other authority than him.
Last night Bradley earned the ire of Mariners' coach Don Wakamatsu by yelling at an umpire from the bench. (He has a habit of doing this.)
Wak told Bradley to cool it. So Bradley then decided the umpire was a secondary annoyance. His real beef was now with his own coach. (He has a habit of doing this too.)
According to ESPN 710, Bradley then walked over to Wak and said, "I'm packing my stuff. I'm out of here." Then left the dugout in a huff.
So let's see. Less than one-fifth of the way through the season and the M's clean-up hitter has already lashed out at the umps and his coach. If you're playing Bradley Blame Game Bingo at home, you're now rooting for public rebukes of GM Jack Zduriencik and the entire city of Seattle. Which should come about in roughly *checks Mariners' schedule* three days.