DENVER, Colo. - United Airlines says regular-paying flyers are welcome to wear leggings aboard its flights, even though two teenage girls were barred by a gate agent from boarding a flight from Denver to Minneapolis Sunday because of their attire.

An airline spokesman said that the girls were traveling under an employee travel pass that includes a dress code.

The move sparked a wave of online criticism against United.

Chris Hrapsky looks at the anatomy of a story, and how it spread so far, so fast -- with a limited amount of information.