(CNN) - Do airline passengers have the right to recline?
That simmering debate among fliers escalated Sunday aboard a United Airlines flight that was diverted after two passengers argued over the use of a device that blocks reclining.
A Knee Defender, a gadget that "helps you stop reclining seats on airplanes so your knees won't have to," was at the root of the disturbance.
United Flight 1462 from Newark to Denver was forced to divert to Chicago's O'Hare airport, according to United Airlines. The airline said that it does not allow the use of the recline-blocking device on its aircraft.
A federal law enforcement source, speaking on background, said the incident involved a male and a female passenger, both 48 years old.