Fliers are very protective of their leg room. One passenger on a Newark to Denver flight this weekend protected his with a pair of Knee Defenders, a device to prevent the chair in front from reclining. He was asked to remove the device and when he refused a fight broke out, with the woman in front of him throwing a cup of water in his direction. The plane was diverted to Chicago and both passengers were forcibly removed. The Knee Defender is a plastic brace that hooks to tray tables and is banned by most U.S. airlines.