Why is Kanye Yelling? [VIDEO]

At a show in London, Kanye yells and yells some more. Then he throws his mic as he disappears off stage. What's the deal Yey?

At gig in London the night earlier, Kanye free styled his anger towards Justin Timberlake's 'Suit and Tie' success as well as the Grammy's. Now it looks like he's throwing another temper-tantrum on stage in this video.