They disrupt airline operations because the systems handle everything from flight dispatching to crew scheduling, from ticket sales to frequent-flier accounts.

WSJ: Delays Hit 1,300 American Airlines Flights

If a flight is canceled for operational reasons (such as a mechanical problem or crew scheduling conflicts) most airline contracts stipulate that you have to be put on the next available flight, even if it's on another airline.

NPR: Don't Pack that Pumpkin Pie Just Yet...

"Each pilot accessed and used his personal laptop computer while they discussed the airline crew flight scheduling procedure, " the report said.

CNN: Report: Stray jet's pilots were on laptops

It said the men were talking about the new monthly crew flight scheduling system put into place in the wake of Northwest's merger with Delta Air Lines.

CNN: Report: Stray jet's pilots were on laptops

It said the men were talking about a new monthly crew flight scheduling system that was put into place in the wake of Northwest's merger with Delta Air Lines.

CNN: Pilots of wayward jet lose licenses