The parents complained the PG-13 movie "Alex Cross" was too violent for their young boys, ages four and eight. They asked if their monitor could be turned off, but the flight attendant said it could not.
The captain then diverted the Denver to Baltimore flight, stopping in Chicago to have the family removed and questioned by the FBI.
In a statement to ABC News, the airline only said, "United flight 638 from Denver to Baltimore diverted to Chicago O'Hare after the crew reported a disturbance involving a passenger. The flight landed without incident and the passengers were removed from the aircraft. We reaccommodated the customers on the next flight to Baltimore and have since conducted a full review of our inflight entertainment."