In 2016, Kaepernick became a national figure when he ignited a firestorm of controversy by choosing to kneel on one knee rather than stand while the United States national anthem was being played before the start of NFL games. He described his behavior as a protest against racial injustice in the United States. His actions prompted negative and positive responses. The negative responses included suggestions that players who protest should be fired; other people displayed their disapproval of players' protests by leaving the stadium immediately after the protests or refusing to watch games at all. Positive responses included similar activity by additional athletes in the NFL and other American sports leagues protesting in various ways during the anthem. In November 2017, Kaepernick filed a grievance against the NFL and its owners, accusing them of colluding to not hire him. In 2018, Amnesty International awarded Kaepernick that year's Ambassador of Conscience award. In 2018 Kaepernick was awarded the W. E. B. Du Bois Medal.