U.S. national anthem protests
Protests during the playing of the United States national anthem have had many causes, including civil rights, anti-conscription, anti-war, anti-nationalism, and religious reservations. Such protests have occurred since at least the 1890s, well before "The Star-Spangled Banner" was adopted and resolved by Congress as the official national anthem in 1916 and 1931, respectively.
Source: Wikipedia — U.S. national anthem protests (CC BY-SA 4.0)