United Airlines barred two young women from boarding their flight Sunday morning because of the kind of pants they were wearing. Many people on social media are talking about the decision. Most say the girls did nothing wrong. The airline says it made the decision because the girls were wearing leggings. Leggings are pants that are made of a material that stretches to fight tightly around the legs. They are a popular kind of clothing for women and girls. That kind of clothing is not in line with its dress code, United says.