From 1974, a brief and touching correspondence between a season's ticket-holding Cleveland Browns fan and the stadium management:
Absolutely Epic 1974 Letter From Cleveland Browns to a Fan (via MeFi)
I am one of your season ticket holders who attends or tries to attend every game. It appears one of the pastimes of several fans has become the sailing of paper airplanes generally made out of the game program. As you know, there is the risk of serious eye injury and perhaps an ear injury as a result of such airplanes. I am sure that this has been called to your attention and that several of your ushers and policemen witnessed the same.