http://www.youtube.com/watch?v=sRYNYb30nxU If you have ever met personally, watched interviews, seen live or even as little as viewed one of their music videos - you can tell within a heartbeat, that they love to never take life too seriously. I believe a large portion of their appeal is seeing how much they enjoy what they do. A quick comparison to a more serious group, such as Scottish rockers Biffy Clyro, there is a distinct difference in atmosphere and general feeling in what to expect in relation to a live performance. The video for I Believe In A Thing Called Love is a great example - there is minimal moments when you can actually take them seriously, however I mean this in a positive way. When they have fun, you have fun with them, and I think the way they do this makes them unique in what they stand for. What other reason could explain Justin's unnecessary nakedness?