In this July 17, 2013 file photo, a United Airlines jet approaching Los Angeles International Airport passes in front of a Waxing Gibbous moon. Airfare is up 10.7 percent in the past five years _ after adjusting for inflation _ according to an Associated Press analysis of data from the Airlines Reporting Corp., which processes ticket transactions for airlines and more than 9,400 travel agencies, including websites such as Expedia and Orbitz. ( AP Photo/Nick Ut, File)
A United Airlines jet
AP Photo

A man and a woman disagreed so badly in the skies this past Sunday that police became involved and their plane was diverted.

They were fighting over a Knee Defender. What is a Knee Defender, you ask?

Why, it’s a nifty little $22 gadget that attaches to a passenger’s tray table and prevents the person in front of him or her from reclining back. Well, perhaps it’s only nifty if you are the one defending your knees.

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According to an Associated Press report, a man sitting in a middle seat on a United Airlines flight used his Knee Defender to stop a lady in front of him from reclining. He was using his laptop. When a flight attendant asked him to remove the Knee Defender, he refused. Then the woman who was denied reclining privileges stood up and threw a cup of water at him. That’s when the Denver-bound plane was diverted to Chicago, where Chicago police were waiting to question the man and woman, both 48 years old. They were not arrested, according to an airport spokesman. But they were not allowed back on their flight.

Is the Knee Defender even allowed? The Federal Aviation Administration leaves it up to individual airlines to decide whether or not the device may be used during flight, reports the Associated Press.

Would you be upset if someone used a Knee Defender on your seat?

This woman would:

But this woman blames the lack of room on airplanes:

Tell us what you think.