A Green Bay Packers fan filed suit against the Chicago Bears in federal court for the Northern District of Illinois on June 16, alleging that the Bears violated his First Amendment rights by barring him from wearing clothing supporting an opposing team while attending on-field events.Russell Beckman, a pro se plaintiff, is a season-ticket holder for both the Bears and the Packers. Beckman is a Wisconsin resident, but he holds on to his Bears tickets solely so he can attend the Bears-Packers game every year; each time clad …