On a recent flight a plane was diverted mid-flight because a passenger was using the Knee Defender, which are two devices that clamp on your tray table preventing the passenger in front of you from reclining. The passenger in front complained, the flight attendant asked the passenger who used the device to remove it, he refused and a "fight" broke out. (the front passenger stood up and threw a glass of water on the passenger behind her)
I fly quite a bit for work and space is very limited. I never recline my seat out of courtesy, but that is a personal choice. So, what is your opinion? Should people be allowed to use this device or not and why/why not?