Both the man with the device, sold as the Knee Defender, and the woman sitting in the seat in front of him were removed from the plane at O'Hare International Airport on Sunday, sources told CNN. Neither was arrested.
Both were passengers on a flight from Newark Liberty International Airport in New Jersey to Denver. The woman complained to a flight attendant about being unable to recline her seat, and when the man refused to remove the device she threw water in his face.
Both were sitting in the Economy Plus section of the plane, where passengers are supposed to get about 5 inches of additional space.
United said it does not allow passengers to use Knee Defenders and similar devices. The Knee Defender is advertised as a device that "helps you stop reclining seats on airplanes so your knees won't have to."