In what has since been described as an over-reaction to events in Paris, law enforcement officers removed three male and one female passengers from a flight scheduled to leave Baltimore-Washington International Airport for Chicago O’Hare International Airport on 17 November. Spirit Airlines flight 969 was taxiing to the runway for its 6 a.m. ET departure when a passenger alerted a flight attendant to another passenger’s “suspicious activity” on board the flight. The "suspicious activity" involved one of the male passengers viewing a news report on his smartphone. The flight attendant notified the captain, who decided to return the plane to the gate.
A Maryland Transportation Authority (MTA) Police spokesperson told ABC News that law enforcement escorted three males and one female off the plane. They were then taken into custody at the airport. All four of the passengers were "very cooperative," according to the MTA spokesperson, and have been released. The spokesman said no charges will be filed and the incident has been "resolved."
TSA re-screened all carry-on and checked bags, and found no safety threats. Spirit Airlines flight 969 eventually departed the Maryland airport at 9:27 a.m. ET and landed in Chicago at 10:05 a.m. CT.
The above info is taken from the ABC News website which includes video and overhead pictures taken from the News 1 helicopter which is featured in the attached audio file.