Watch this movie and ask that question again...
http://www.youtube.com/watch?v=8LdeySxbsHM
http://www.youtube.com/watch?v=AXrFoGROme8&feature=related
http://www.youtube.com/watch?v=F4VjmeaQNv0&feature=related
http://www.youtube.com/watch?v=SFChZGmYWhM&feature=related