In 2005 the Northwestern University women's lacrosse team won an NCAA championship and was invited to the White House to receive congratulations from the president. Controversy erupted after their visit, when the official photograph revealed that several team members were wearing flip-flops. Despite the outcry, the athletes took the criticism in stride, talking about it on the Today Show and auctioning the offending footwear for charity. Given the reaction and the team's response, what sort of norm did the athletes break by wearing flip-flops to the White House?