It's a form of expression or a shot at attention depending on the message. I don't think they are stupid. For alot of people a show is their chance to communicate with the band, to let them know how they feel. i'm not saying it's rational or logical but i've seen some pretty creative ones over the years and it is fun, especially if it catches Jon's eye and he acknowledges it. i agree with Becky that you should put them down during songs if you are blocking the view. Jon has been known to play a song request now and then and he talks about reading banners and forgetting what he's supposed to be doing. The band likes them so I guess we'll be seeing them forever.